diff --git a/app/config/admin/services.yml b/app/config/admin/services.yml
index caad57d5e04e0..9b43c04b87c65 100644
--- a/app/config/admin/services.yml
+++ b/app/config/admin/services.yml
@@ -1,10 +1,15 @@
 # Dedicated services for Admin app
 parameters:
-  # All admin context listeners should be executed before the router listener, this way even if no symfony route is found they context are initialized
+  # We set priorities lower than the RouterListener (32) so that the LegacyRouterChecker class is called first.
+  # The correct behaviour of Context Listeners on legacy routes depends on LegacyRouterChecker.
+  employee_listener_priority: 31
+  language_listener_priority: 30
+  default_listener_priority: 29
+  # All admin context listeners should be executed before the router listener, this way even if no symfony route is found the contexts are initialized correctly
   # and can be used in admin legacy pages as well (router listener priority is 32)
-  employee_listener_priority: 35
-  language_listener_priority: 34
-  default_listener_priority: 33
+  legacy_employee_listener_priority: 35
+  legacy_language_listener_priority: 34
+  legacy_default_listener_priority: 33
 
 services:
   _defaults:
@@ -75,26 +80,79 @@ services:
 
   # Employee context must have a higher priority because Shop and Language depend on it
   PrestaShopBundle\EventListener\Admin\Context\EmployeeContextListener:
+    arguments:
+      $isSymfonyLayout: true
     tags:
       - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%employee_listener_priority%' }
 
+  PrestaShopBundle\EventListener\Admin\Context\EmployeeContextListener.legacy:
+    class: PrestaShopBundle\EventListener\Admin\Context\EmployeeContextListener
+    arguments:
+      $isSymfonyLayout: false
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_employee_listener_priority%' }
+
+  PrestaShopBundle\EventListener\Admin\Context\DefaultLanguageContextListener:
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_language_listener_priority%' }
+
   # Language depends on Employee so its priority is lower, however it has higher priority than Currency and Country because they depend on Language
   PrestaShopBundle\EventListener\Admin\Context\LanguageContextListener:
+    arguments:
+      $isSymfonyLayout: true
     tags:
       - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%language_listener_priority%' }
 
+  PrestaShopBundle\EventListener\Admin\Context\LanguageContextListener.legacy:
+    class: PrestaShopBundle\EventListener\Admin\Context\LanguageContextListener
+    arguments:
+      $isSymfonyLayout: false
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_language_listener_priority%' }
+
+  PrestaShopBundle\EventListener\Admin\Context\DefaultShopContextListener:
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_default_listener_priority%' }
+
   PrestaShopBundle\EventListener\Admin\Context\ShopContextListener:
+    arguments:
+      $isSymfonyLayout: true
     tags:
       - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%default_listener_priority%' }
 
+  PrestaShopBundle\EventListener\Admin\Context\ShopContextListener.legacy:
+    class: PrestaShopBundle\EventListener\Admin\Context\ShopContextListener
+    arguments:
+      $isSymfonyLayout: false
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_default_listener_priority%' }
+
   PrestaShopBundle\EventListener\Admin\Context\CurrencyContextListener:
+    arguments:
+      $isSymfonyLayout: true
     tags:
       - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%default_listener_priority%' }
 
+  PrestaShopBundle\EventListener\Admin\Context\CurrencyContextListener.legacy:
+    class: PrestaShopBundle\EventListener\Admin\Context\CurrencyContextListener
+    arguments:
+      $isSymfonyLayout: false
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_default_listener_priority%' }
+
   PrestaShopBundle\EventListener\Admin\Context\CountryContextListener:
+    arguments:
+      $isSymfonyLayout: true
     tags:
       - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%default_listener_priority%' }
 
+  PrestaShopBundle\EventListener\Admin\Context\CountryContextListener.legacy:
+    class: PrestaShopBundle\EventListener\Admin\Context\CountryContextListener
+    arguments:
+      $isSymfonyLayout: false
+    tags:
+      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest, priority: '%legacy_default_listener_priority%' }
+
   # This listener must run after the router listener since it's based on the request attributes that are defined by the router
   PrestaShopBundle\EventListener\Admin\Context\LegacyControllerContextListener:
     tags:
diff --git a/classes/controller/AdminController.php b/classes/controller/AdminController.php
index 049da14c80a74..e7a873026b94a 100644
--- a/classes/controller/AdminController.php
+++ b/classes/controller/AdminController.php
@@ -4395,7 +4395,7 @@ protected function setAllowAnonymous($value)
      *
      * @return bool
      */
-    protected function isAnonymousAllowed()
+    public function isAnonymousAllowed()
     {
         return $this->allowAnonymous;
     }
diff --git a/src/Adapter/Security/Admin.php b/src/Adapter/Security/Admin.php
index 074229adbbda0..d8f67ca267093 100644
--- a/src/Adapter/Security/Admin.php
+++ b/src/Adapter/Security/Admin.php
@@ -28,8 +28,8 @@
 
 use Context;
 use PrestaShop\PrestaShop\Adapter\LegacyContext;
+use PrestaShopBundle\Routing\LegacyControllerConstants;
 use Symfony\Component\HttpFoundation\RedirectResponse;
-use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
@@ -89,7 +89,8 @@ public function __construct(
      */
     public function onKernelRequest(RequestEvent $event): void
     {
-        if ($this->security->getUser() !== null) {
+        $publicLegacyRoute = $event->getRequest()->attributes->get(LegacyControllerConstants::ANONYMOUS_ATTRIBUTE);
+        if ($this->security->getUser() !== null || $publicLegacyRoute) {
             return;
         }
 
diff --git a/src/Core/Context/LegacyControllerContextBuilder.php b/src/Core/Context/LegacyControllerContextBuilder.php
index 5e96c00d3d218..7a883b4b49764 100644
--- a/src/Core/Context/LegacyControllerContextBuilder.php
+++ b/src/Core/Context/LegacyControllerContextBuilder.php
@@ -88,6 +88,12 @@ public function build(): LegacyControllerContext
 
     public function buildLegacyContext(): void
     {
+        // In legacy pages the AdminController class already sets the context's controller, which is a more accurate
+        // candidate than our facade meant for backward compatibility, so we leave it untouched
+        if ($this->contextStateManager->getContext()->controller) {
+            return;
+        }
+
         $this->assertArguments();
 
         if (null === $this->_legacyControllerContext) {
diff --git a/src/PrestaShopBundle/Controller/Admin/LegacyController.php b/src/PrestaShopBundle/Controller/Admin/LegacyController.php
index 3a3e1804f1ec6..2f0c970f77a38 100644
--- a/src/PrestaShopBundle/Controller/Admin/LegacyController.php
+++ b/src/PrestaShopBundle/Controller/Admin/LegacyController.php
@@ -32,7 +32,7 @@
 use PrestaShop\PrestaShop\Core\ConfigurationInterface;
 use PrestaShop\PrestaShop\Core\Exception\CoreException;
 use PrestaShopBundle\Entity\Repository\TabRepository;
-use PrestaShopBundle\Routing\LegacyRouterChecker;
+use PrestaShopBundle\Routing\LegacyControllerConstants;
 use PrestaShopBundle\Twig\Layout\MenuBuilder;
 use PrestaShopBundle\Twig\Layout\SmartyVariablesFiller;
 use SmartyException;
@@ -84,11 +84,11 @@ public function legacyPageAction(Request $request): Response
         // These parameters have already been set as request attributes by LegacyRouterChecker
         $dispatcherHookParameters = [
             'controller_type' => Dispatcher::FC_ADMIN,
-            'controller_class' => $request->attributes->get(LegacyRouterChecker::LEGACY_CONTROLLER_CLASS_ATTRIBUTE),
-            'is_module' => $request->attributes->get(LegacyRouterChecker::LEGACY_CONTROLLER_IS_MODULE_ATTRIBUTE),
+            'controller_class' => $request->attributes->get(LegacyControllerConstants::CLASS_ATTRIBUTE),
+            'is_module' => $request->attributes->get(LegacyControllerConstants::IS_MODULE_ATTRIBUTE),
         ];
 
-        $adminController = $this->initController($dispatcherHookParameters);
+        $adminController = $this->initController($request, $dispatcherHookParameters);
         // Redirect if necessary after post process
         if (!empty($adminController->getRedirectAfter())) {
             // After each request the cookie must be written to save its modified state during AdminController workflow
@@ -196,30 +196,8 @@ protected function renderAjaxController(AdminController $adminController, string
         } elseif (method_exists($adminController, 'displayAjax')) {
             $adminController->displayAjax();
         }
-        $outputContent = ob_get_clean();
 
-        // The output of the controller is either directly echoed or it can be properly appended in AdminController::content
-        // it depends on the implementation of the controllers.
-        if (!empty($outputContent) && !empty($adminController->content)) {
-            // Sometimes they are both done and are equal, in which case we only return one content to avoid duplicates.
-            if ($outputContent === $adminController->content) {
-                $responseContent = $outputContent;
-            } else {
-                // In case both contents are present and are different we concatenate them, first the echoed output and then the controller
-                // one since it is displayed last by smarty in the original workflow
-                // This concatenation approach is theoretical and naive and was not tested because of the lack of use cases, so it may need
-                // to be improved in the future
-                $responseContent = $outputContent . $adminController->content;
-            }
-        } elseif (!empty($outputContent)) {
-            $responseContent = $outputContent;
-        } elseif (!empty($adminController->content)) {
-            $responseContent = $adminController->content;
-        } else {
-            $responseContent = '';
-        }
-
-        return new Response($responseContent);
+        return new Response(ob_get_clean());
     }
 
     /**
@@ -228,17 +206,16 @@ protected function renderAjaxController(AdminController $adminController, string
      *
      * Note: some legacy controllers may already use die at this point (to echo content and finish the process) when postProcess is called.
      *
+     * @param Request $request
      * @param array $dispatcherHookParameters
      *
      * @return AdminController
      */
-    protected function initController(array $dispatcherHookParameters): AdminController
+    protected function initController(Request $request, array $dispatcherHookParameters): AdminController
     {
-        $controllerClass = $dispatcherHookParameters['controller_class'];
-
-        // Loading controller
+        // Retrieving the controller instantiated in LegacyRouterChecker
         /** @var AdminController $adminController */
-        $adminController = new $controllerClass();
+        $adminController = $request->attributes->get(LegacyControllerConstants::INSTANCE_ATTRIBUTE);
 
         // Fill default smarty variables as they can be used in partial templates rendered in init methods
         $this->assignSmartyVariables->fillDefault();
@@ -248,7 +225,6 @@ protected function initController(array $dispatcherHookParameters): AdminControl
 
         // This part comes from AdminController::run method, it has been stripped from permission checks since the permission is already
         // handled by this Symfony controller
-        $adminController->init();
         $adminController->setMedia(false);
         $adminController->postProcess();
 
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/CountryContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/CountryContextListener.php
index e061f5d517fce..0f778872064a6 100644
--- a/src/PrestaShopBundle/EventListener/Admin/Context/CountryContextListener.php
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/CountryContextListener.php
@@ -30,6 +30,8 @@
 
 use PrestaShop\PrestaShop\Core\ConfigurationInterface;
 use PrestaShop\PrestaShop\Core\Context\CountryContextBuilder;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 
 /**
@@ -39,7 +41,9 @@ class CountryContextListener
 {
     public function __construct(
         private readonly CountryContextBuilder $countryContextBuilder,
-        private readonly ConfigurationInterface $configuration
+        private readonly ConfigurationInterface $configuration,
+        private readonly FeatureFlagStateCheckerInterface $featureFlagStateChecker,
+        private readonly bool $isSymfonyLayout,
     ) {
     }
 
@@ -49,6 +53,10 @@ public function onKernelRequest(RequestEvent $event): void
             return;
         }
 
+        if ($this->isSymfonyLayout !== $this->featureFlagStateChecker->isEnabled(FeatureFlagSettings::FEATURE_FLAG_SYMFONY_LAYOUT)) {
+            return;
+        }
+
         $this->countryContextBuilder->setCountryId((int) $this->configuration->get('PS_COUNTRY_DEFAULT'));
     }
 }
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListener.php
index 41e5f53d24522..916fa46f8394b 100644
--- a/src/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListener.php
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListener.php
@@ -30,6 +30,8 @@
 
 use PrestaShop\PrestaShop\Core\ConfigurationInterface;
 use PrestaShop\PrestaShop\Core\Context\CurrencyContextBuilder;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 
 /**
@@ -40,6 +42,8 @@ class CurrencyContextListener
     public function __construct(
         private readonly CurrencyContextBuilder $currencyContextBuilder,
         private readonly ConfigurationInterface $configuration,
+        private readonly FeatureFlagStateCheckerInterface $featureFlagStateChecker,
+        private readonly bool $isSymfonyLayout,
     ) {
     }
 
@@ -49,6 +53,10 @@ public function onKernelRequest(RequestEvent $event): void
             return;
         }
 
+        if ($this->isSymfonyLayout !== $this->featureFlagStateChecker->isEnabled(FeatureFlagSettings::FEATURE_FLAG_SYMFONY_LAYOUT)) {
+            return;
+        }
+
         $this->currencyContextBuilder->setCurrencyId((int) $this->configuration->get('PS_CURRENCY_DEFAULT'));
     }
 }
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/DefaultLanguageContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/DefaultLanguageContextListener.php
new file mode 100644
index 0000000000000..3371e2a9a14eb
--- /dev/null
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/DefaultLanguageContextListener.php
@@ -0,0 +1,58 @@
+<?php
+/**
+ * Copyright since 2007 PrestaShop SA and Contributors
+ * PrestaShop is an International Registered Trademark & Property of PrestaShop SA
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.md.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://devdocs.prestashop.com/ for more information.
+ *
+ * @author    PrestaShop SA and Contributors <contact@prestashop.com>
+ * @copyright Since 2007 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ */
+
+declare(strict_types=1);
+
+namespace PrestaShopBundle\EventListener\Admin\Context;
+
+use PrestaShop\PrestaShop\Core\ConfigurationInterface;
+use PrestaShop\PrestaShop\Core\Context\LanguageContextBuilder;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+
+/**
+ * Listener dedicated to set up default Language context for the Back-Office/Admin application.
+ * We need to initialize the LanguageContext earlier because it's used by components in the Symfony
+ * layout that will be displayed in the Not Found legacy page
+ */
+class DefaultLanguageContextListener
+{
+    public function __construct(
+        private readonly LanguageContextBuilder $languageContextBuilder,
+        private readonly ConfigurationInterface $configuration,
+    ) {
+    }
+
+    public function onKernelRequest(RequestEvent $event): void
+    {
+        if (!$event->isMainRequest()) {
+            return;
+        }
+
+        $defaultLanguageId = (int) $this->configuration->get('PS_LANG_DEFAULT');
+        $this->languageContextBuilder->setDefaultLanguageId($defaultLanguageId);
+        $this->languageContextBuilder->setLanguageId($defaultLanguageId);
+    }
+}
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/DefaultShopContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/DefaultShopContextListener.php
new file mode 100644
index 0000000000000..dc8edba59dfed
--- /dev/null
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/DefaultShopContextListener.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ * Copyright since 2007 PrestaShop SA and Contributors
+ * PrestaShop is an International Registered Trademark & Property of PrestaShop SA
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.md.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://devdocs.prestashop.com/ for more information.
+ *
+ * @author    PrestaShop SA and Contributors <contact@prestashop.com>
+ * @copyright Since 2007 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ */
+
+declare(strict_types=1);
+
+namespace PrestaShopBundle\EventListener\Admin\Context;
+
+use PrestaShop\PrestaShop\Core\Context\ShopContextBuilder;
+use PrestaShop\PrestaShop\Core\Domain\Configuration\ShopConfigurationInterface;
+use PrestaShop\PrestaShop\Core\Domain\Shop\Exception\ShopException;
+use PrestaShop\PrestaShop\Core\Domain\Shop\ValueObject\ShopConstraint;
+use Symfony\Component\HttpKernel\Event\RequestEvent;
+
+/**
+ * Listener dedicated to set up default Shop context for the Back-Office/Admin application.
+ * We need to initialize the ShopContext earlier because it's used by components in the Symfony
+ * layout that will be displayed in the Not Found legacy page
+ */
+class DefaultShopContextListener
+{
+    public function __construct(
+        private readonly ShopContextBuilder $shopContextBuilder,
+        private readonly ShopConfigurationInterface $configuration,
+    ) {
+    }
+
+    /**
+     * @throws ShopException
+     */
+    public function onKernelRequest(RequestEvent $event): void
+    {
+        if (!$event->isMainRequest()) {
+            return;
+        }
+        $shopConstraint = ShopConstraint::shop((int) $this->configuration->get('PS_SHOP_DEFAULT', null, ShopConstraint::allShops()));
+        $this->shopContextBuilder->setShopId($shopConstraint->getShopId()->getValue());
+        $this->shopContextBuilder->setShopConstraint($shopConstraint);
+    }
+}
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListener.php
index 6387bcdcc55a1..c17c94ba9162d 100644
--- a/src/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListener.php
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListener.php
@@ -30,6 +30,8 @@
 
 use PrestaShop\PrestaShop\Adapter\LegacyContext;
 use PrestaShop\PrestaShop\Core\Context\EmployeeContextBuilder;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use PrestaShopBundle\Security\Admin\Employee;
 use Symfony\Bundle\SecurityBundle\Security;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
@@ -43,6 +45,8 @@ public function __construct(
         private readonly EmployeeContextBuilder $employeeContextBuilder,
         private readonly LegacyContext $legacyContext,
         private readonly Security $security,
+        private readonly FeatureFlagStateCheckerInterface $featureFlagStateChecker,
+        private readonly bool $isSymfonyLayout,
     ) {
     }
 
@@ -52,6 +56,10 @@ public function onKernelRequest(RequestEvent $event): void
             return;
         }
 
+        if ($this->isSymfonyLayout !== $this->featureFlagStateChecker->isEnabled(FeatureFlagSettings::FEATURE_FLAG_SYMFONY_LAYOUT)) {
+            return;
+        }
+
         if (!empty($this->legacyContext->getContext()->cookie->id_employee)) {
             $this->employeeContextBuilder->setEmployeeId((int) $this->legacyContext->getContext()->cookie->id_employee);
         } elseif ($this->security->getUser() instanceof Employee) {
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListener.php
index 1fa4f0e648b8c..41fd9aec7bc9c 100644
--- a/src/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListener.php
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListener.php
@@ -28,9 +28,10 @@
 
 namespace PrestaShopBundle\EventListener\Admin\Context;
 
-use PrestaShop\PrestaShop\Core\ConfigurationInterface;
 use PrestaShop\PrestaShop\Core\Context\EmployeeContext;
 use PrestaShop\PrestaShop\Core\Context\LanguageContextBuilder;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 
 /**
@@ -41,7 +42,8 @@ class LanguageContextListener
     public function __construct(
         private readonly LanguageContextBuilder $languageContextBuilder,
         private readonly EmployeeContext $employeeContext,
-        private readonly ConfigurationInterface $configuration,
+        private readonly FeatureFlagStateCheckerInterface $featureFlagStateChecker,
+        private readonly bool $isSymfonyLayout,
     ) {
     }
 
@@ -51,15 +53,12 @@ public function onKernelRequest(RequestEvent $event): void
             return;
         }
 
-        $defaultLanguageId = (int) $this->configuration->get('PS_LANG_DEFAULT');
-        $this->languageContextBuilder->setDefaultLanguageId($defaultLanguageId);
-
+        if ($this->isSymfonyLayout !== $this->featureFlagStateChecker->isEnabled(FeatureFlagSettings::FEATURE_FLAG_SYMFONY_LAYOUT)) {
+            return;
+        }
         if ($this->employeeContext->getEmployee()) {
             // Use the employee language if available
             $this->languageContextBuilder->setLanguageId($this->employeeContext->getEmployee()->getLanguageId());
-        } else {
-            // If not use the default language of the shop
-            $this->languageContextBuilder->setLanguageId($defaultLanguageId);
         }
     }
 }
diff --git a/src/PrestaShopBundle/EventListener/Admin/Context/ShopContextListener.php b/src/PrestaShopBundle/EventListener/Admin/Context/ShopContextListener.php
index 9d28c7b360405..9c575a222ed42 100644
--- a/src/PrestaShopBundle/EventListener/Admin/Context/ShopContextListener.php
+++ b/src/PrestaShopBundle/EventListener/Admin/Context/ShopContextListener.php
@@ -35,8 +35,11 @@
 use PrestaShop\PrestaShop\Core\Domain\Configuration\ShopConfigurationInterface;
 use PrestaShop\PrestaShop\Core\Domain\Shop\Exception\ShopException;
 use PrestaShop\PrestaShop\Core\Domain\Shop\ValueObject\ShopConstraint;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use PrestaShop\PrestaShop\Core\Util\Url\UrlCleaner;
 use PrestaShopBundle\Controller\Attribute\AllShopContext;
+use PrestaShopBundle\Routing\LegacyControllerConstants;
 use ReflectionClass;
 use ReflectionException;
 use Symfony\Component\HttpFoundation\RedirectResponse;
@@ -57,6 +60,8 @@ public function __construct(
         private readonly LegacyContext $legacyContext,
         private readonly MultistoreFeature $multistoreFeature,
         private readonly RouterInterface $router,
+        private readonly FeatureFlagStateCheckerInterface $featureFlagStateChecker,
+        private readonly bool $isSymfonyLayout,
     ) {
     }
 
@@ -69,6 +74,11 @@ public function onKernelRequest(RequestEvent $event): void
         if (!$event->isMainRequest()) {
             return;
         }
+
+        if ($this->isSymfonyLayout !== $this->featureFlagStateChecker->isEnabled(FeatureFlagSettings::FEATURE_FLAG_SYMFONY_LAYOUT)) {
+            return;
+        }
+
         $psSslEnabled = (bool) $this->configuration->get('PS_SSL_ENABLED', null, ShopConstraint::allShops());
 
         $this->shopContextBuilder->setSecureMode($psSslEnabled && $event->getRequest()->isSecure());
@@ -116,6 +126,13 @@ private function getMultiShopConstraint(Request $request): ShopConstraint
         }
 
         $shopConstraint = ShopConstraint::allShops();
+        // Check if the displayed legacy controller forces All shops mode (check already performed by LegacyRouterChecker)
+        $isAllShopContext = $request->attributes->get(LegacyControllerConstants::IS_ALL_SHOP_CONTEXT_ATTRIBUTE);
+
+        if ($isAllShopContext) {
+            return $shopConstraint;
+        }
+
         $cookieShopConstraint = $this->getShopConstraintFromCookie();
         if ($cookieShopConstraint) {
             if ($cookieShopConstraint->getShopGroupId()) {
diff --git a/src/PrestaShopBundle/EventListener/Admin/TokenizedUrlsListener.php b/src/PrestaShopBundle/EventListener/Admin/TokenizedUrlsListener.php
index b82b54bbd39db..7ac8ac2cd9d23 100644
--- a/src/PrestaShopBundle/EventListener/Admin/TokenizedUrlsListener.php
+++ b/src/PrestaShopBundle/EventListener/Admin/TokenizedUrlsListener.php
@@ -28,6 +28,7 @@
 
 use PrestaShop\PrestaShop\Core\Feature\TokenInUrls;
 use PrestaShop\PrestaShop\Core\Util\Url\UrlCleaner;
+use PrestaShopBundle\Routing\LegacyControllerConstants;
 use PrestaShopBundle\Security\Admin\UserTokenManager;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpKernel\Event\KernelEvent;
@@ -50,8 +51,9 @@ public function __construct(
     public function onKernelRequest(KernelEvent $event)
     {
         $request = $event->getRequest();
+        $publicLegacyRoute = $event->getRequest()->attributes->get(LegacyControllerConstants::ANONYMOUS_ATTRIBUTE);
 
-        if (TokenInUrls::isDisabled()) {
+        if (TokenInUrls::isDisabled() || $publicLegacyRoute) {
             return;
         }
 
diff --git a/src/PrestaShopBundle/Routing/LegacyControllerConstants.php b/src/PrestaShopBundle/Routing/LegacyControllerConstants.php
new file mode 100644
index 0000000000000..ea26287f57e08
--- /dev/null
+++ b/src/PrestaShopBundle/Routing/LegacyControllerConstants.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PrestaShopBundle\Routing;
+
+class LegacyControllerConstants
+{
+    public const CLASS_ATTRIBUTE = '_legacy_controller_class';
+    public const INSTANCE_ATTRIBUTE = '_legacy_controller_instance';
+    public const ANONYMOUS_ATTRIBUTE = '_legacy_controller_anonymous';
+    public const IS_MODULE_ATTRIBUTE = '_legacy_controller_is_module';
+    public const IS_ALL_SHOP_CONTEXT_ATTRIBUTE = '_legacy_controller_is_all_shop_context';
+}
diff --git a/src/PrestaShopBundle/Routing/LegacyRouterChecker.php b/src/PrestaShopBundle/Routing/LegacyRouterChecker.php
index f228e33583932..b0a71e1c4097c 100644
--- a/src/PrestaShopBundle/Routing/LegacyRouterChecker.php
+++ b/src/PrestaShopBundle/Routing/LegacyRouterChecker.php
@@ -29,6 +29,7 @@
 namespace PrestaShopBundle\Routing;
 
 use Dispatcher;
+use PrestaShop\PrestaShop\Core\Domain\Shop\ValueObject\ShopConstraint;
 use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagSettings;
 use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use PrestaShop\PrestaShop\Core\Hook\HookDispatcherInterface;
@@ -44,9 +45,6 @@
 #[AsRoutingConditionService(priority: -1)]
 class LegacyRouterChecker
 {
-    public const LEGACY_CONTROLLER_CLASS_ATTRIBUTE = '_legacy_controller_class';
-    public const LEGACY_CONTROLLER_IS_MODULE_ATTRIBUTE = '_legacy_controller_is_module';
-
     public function __construct(
         protected readonly FeatureFlagStateCheckerInterface $featureFlagStateChecker,
         protected readonly TabRepository $tabRepository,
@@ -111,13 +109,24 @@ public function check(Request $request): bool
             // It's clearer to actually return a not found exception, for now the dispatcher is still used as fallback in index.php
             // but when it's cleared and only Symfony handles the whole routing then we can display a proper not found Symfony page
             if (!isset($controllers[strtolower($queryController)])) {
-                throw new NotFoundHttpException(sprintf('Unknown controller %s', $queryController));
+                $controllerClass = 'AdminNotFoundController';
+            } else {
+                $controllerClass = $controllers[strtolower($queryController)];
             }
-
-            $controllerClass = $controllers[strtolower($queryController)];
         }
-        $request->attributes->set(self::LEGACY_CONTROLLER_CLASS_ATTRIBUTE, $controllerClass);
-        $request->attributes->set(self::LEGACY_CONTROLLER_IS_MODULE_ATTRIBUTE, $isModule);
+        // We load the controller early in the process (during router matching actually), because the controller
+        // configuration has many impacts on the contexts, the security listeners, ... And the relevant data can
+        // only be retrieved once the legacy class is instantiated to access its public configuration
+        // But for performance issues we only instantiate (and init) the controller here once and then store it (along
+        // with other related attributes) in the request attributes so they can be retrieved easily by the code depending on them
+        $adminController = new $controllerClass();
+        $adminController->init();
+
+        $request->attributes->set(LegacyControllerConstants::INSTANCE_ATTRIBUTE, $adminController);
+        $request->attributes->set(LegacyControllerConstants::ANONYMOUS_ATTRIBUTE, $adminController->isAnonymousAllowed());
+        $request->attributes->set(LegacyControllerConstants::IS_ALL_SHOP_CONTEXT_ATTRIBUTE, $adminController->multishop_context === ShopConstraint::ALL_SHOPS);
+        $request->attributes->set(LegacyControllerConstants::CLASS_ATTRIBUTE, $controllerClass);
+        $request->attributes->set(LegacyControllerConstants::IS_MODULE_ATTRIBUTE, $isModule);
 
         return true;
     }
diff --git a/tests/UI/pages/BO/BObasePage.ts b/tests/UI/pages/BO/BObasePage.ts
index 55e0a22e91ce3..7babb4dfc9b74 100644
--- a/tests/UI/pages/BO/BObasePage.ts
+++ b/tests/UI/pages/BO/BObasePage.ts
@@ -256,9 +256,13 @@ export default class BOBasePage extends CommonPage {
 
   private readonly helpDocumentURL: string;
 
-  private readonly invalidTokenContinueLink: string;
+  private readonly invalidTokenContinueLinkLegacy: string;
 
-  private readonly invalidTokenCancelLink: string;
+  private readonly invalidTokenCancelLinkLegacy: string;
+
+  private readonly invalidTokenContinueLinkSymfony: string;
+
+  private readonly invalidTokenCancelLinkSymfony: string;
 
   public readonly debugModeToolbar: string;
 
@@ -613,8 +617,10 @@ export default class BOBasePage extends CommonPage {
     this.helpDocumentURL = `${this.rightSidebar} div.quicknav-scroller._fullspace object`;
 
     // Invalid token block
-    this.invalidTokenContinueLink = 'a.btn-continue';
-    this.invalidTokenCancelLink = 'a.btn-cancel';
+    this.invalidTokenContinueLinkLegacy = 'a.btn-continue';
+    this.invalidTokenCancelLinkLegacy = 'a.btn-cancel';
+    this.invalidTokenContinueLinkSymfony = '#security-compromised-page #csrf-white-container div a:nth-child(1)';
+    this.invalidTokenCancelLinkSymfony = '#security-compromised-page #csrf-white-container div a:nth-child(2)';
   }
 
   /*
@@ -1161,10 +1167,18 @@ export default class BOBasePage extends CommonPage {
    */
   async navigateToPageWithInvalidToken(page: Page, url: string, continueToPage: boolean = true): Promise<void> {
     await this.goTo(page, url);
-    if (await this.elementVisible(page, this.invalidTokenContinueLink, 10000)) {
+    // Legacy Layout
+    if (await this.elementVisible(page, this.invalidTokenContinueLinkLegacy, 10000)) {
+      await this.clickAndWaitForURL(
+        page,
+        continueToPage ? this.invalidTokenContinueLinkLegacy : this.invalidTokenCancelLinkLegacy,
+      );
+    }
+    // Symfony Layout
+    if (await this.elementVisible(page, this.invalidTokenContinueLinkSymfony, 10000)) {
       await this.clickAndWaitForURL(
         page,
-        continueToPage ? this.invalidTokenContinueLink : this.invalidTokenCancelLink,
+        continueToPage ? this.invalidTokenContinueLinkSymfony : this.invalidTokenCancelLinkSymfony,
       );
     }
   }
diff --git a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CountryContextListenerTest.php b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CountryContextListenerTest.php
index 4d38cc54b66d0..9ca90cf155600 100644
--- a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CountryContextListenerTest.php
+++ b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CountryContextListenerTest.php
@@ -48,6 +48,8 @@ public function testKernelRequest(): void
         $listener = new CountryContextListener(
             $countryContextBuilder,
             $this->mockConfiguration(['PS_COUNTRY_DEFAULT' => 42]),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
 
         $event = $this->createRequestEvent(new Request());
diff --git a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListenerTest.php b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListenerTest.php
index d4cb44eff8269..0a93688d0c88f 100644
--- a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListenerTest.php
+++ b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/CurrencyContextListenerTest.php
@@ -48,6 +48,8 @@ public function testKernelRequest(): void
         $listener = new CurrencyContextListener(
             $currencyContextBuilder,
             $this->mockConfiguration(['PS_CURRENCY_DEFAULT' => 42]),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
 
         $event = $this->createRequestEvent(new Request());
diff --git a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListenerTest.php b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListenerTest.php
index cabfc0761c9ed..e82f9dc50b3cc 100644
--- a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListenerTest.php
+++ b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/EmployeeContextListenerTest.php
@@ -46,7 +46,9 @@ public function testFindEmployee(): void
         $listener = new EmployeeContextListener(
             $employeeBuilder,
             $this->mockLegacyContext(['id_employee' => 42]),
-            $this->createMock(Security::class)
+            $this->createMock(Security::class),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
 
         $event = $this->createRequestEvent(new Request());
@@ -63,7 +65,9 @@ public function testEmployeeNotFound(): void
         $listener = new EmployeeContextListener(
             $employeeBuilder,
             $this->mockLegacyContext(['id_employee' => null]),
-            $this->createMock(Security::class)
+            $this->createMock(Security::class),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
         $listener->onKernelRequest($event);
         $this->assertEquals(null, $this->getPrivateField($employeeBuilder, 'employeeId'));
@@ -81,7 +85,9 @@ public function testEmployeeFromSymfonySecurity(): void
         $listener = new EmployeeContextListener(
             $employeeBuilder,
             $this->mockLegacyContext(['id_employee' => null]),
-            $securityMock
+            $securityMock,
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
 
         $event = $this->createRequestEvent(new Request());
diff --git a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListenerTest.php b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListenerTest.php
index ccaef27af1201..b94c80a031c7e 100644
--- a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListenerTest.php
+++ b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/LanguageContextListenerTest.php
@@ -36,6 +36,7 @@
 use PrestaShop\PrestaShop\Core\Context\LanguageContextBuilder;
 use PrestaShop\PrestaShop\Core\Language\LanguageRepositoryInterface;
 use PrestaShop\PrestaShop\Core\Localization\Locale\RepositoryInterface;
+use PrestaShopBundle\EventListener\Admin\Context\DefaultLanguageContextListener;
 use PrestaShopBundle\EventListener\Admin\Context\LanguageContextListener;
 use Symfony\Component\HttpFoundation\Request;
 use Tests\Unit\PrestaShopBundle\EventListener\ContextEventListenerTestCase;
@@ -56,7 +57,8 @@ public function testContextEmployeeLanguage(): void
         $listener = new LanguageContextListener(
             $languageContextBuilder,
             $this->mockEmployeeContext(self::EMPLOYEE_CONTEXT_LANGUAGE_ID),
-            $this->mockConfiguration(),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
 
         $event = $this->createRequestEvent(new Request());
@@ -72,9 +74,8 @@ public function testDefaultConfigurationLanguage(): void
             $this->createMock(ContextStateManager::class),
             $this->createMock(ObjectModelLanguageRepository::class)
         );
-        $listener = new LanguageContextListener(
+        $listener = new DefaultLanguageContextListener(
             $languageContextBuilder,
-            $this->mockEmployeeContext(null),
             $this->mockConfiguration(['PS_LANG_DEFAULT' => self::DEFAULT_CONFIGURATION_LANGUAGE_ID]),
         );
 
diff --git a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/ShopContextListenerTest.php b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/ShopContextListenerTest.php
index cf841b07cae7f..9643db9451929 100644
--- a/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/ShopContextListenerTest.php
+++ b/tests/Unit/PrestaShopBundle/EventListener/Admin/Context/ShopContextListenerTest.php
@@ -61,7 +61,9 @@ public function testSingleShop(): void
             $this->mockConfiguration(['PS_SHOP_DEFAULT' => self::DEFAULT_SHOP_ID, 'PS_SSL_ENABLED' => self::PS_SSL_ENABLED]),
             $this->mockLegacyContext(['shopContext' => '']),
             $this->mockMultistoreFeature(false),
-            $this->mockRouter()
+            $this->mockRouter(),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
         $listener->onKernelRequest($event);
 
@@ -94,7 +96,9 @@ public function testMultiShop(string $cookieValue, ?array $employeeData, ShopCon
             $this->mockConfiguration(['PS_SHOP_DEFAULT' => self::DEFAULT_SHOP_ID, 'PS_SSL_ENABLED' => self::PS_SSL_ENABLED]),
             $this->mockLegacyContext(['shopContext' => $cookieValue]),
             $this->mockMultistoreFeature(true),
-            $this->mockRouter()
+            $this->mockRouter(),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
         $listener->onKernelRequest($event);
 
@@ -169,7 +173,9 @@ public function testMultiShopRedirection(string $switchParameterValue, ?string $
             $this->mockConfiguration(['PS_SHOP_DEFAULT' => self::DEFAULT_SHOP_ID, 'PS_SSL_ENABLED' => self::PS_SSL_ENABLED]),
             $mockContext,
             $this->mockMultistoreFeature(true),
-            $this->mockRouter()
+            $this->mockRouter(),
+            $this->mockFeatureFlagStateChecker(),
+            true,
         );
 
         // Check that initially the cookie has a null value
diff --git a/tests/Unit/PrestaShopBundle/EventListener/ContextEventListenerTestCase.php b/tests/Unit/PrestaShopBundle/EventListener/ContextEventListenerTestCase.php
index da48809efbc5f..3f1b80435dae7 100644
--- a/tests/Unit/PrestaShopBundle/EventListener/ContextEventListenerTestCase.php
+++ b/tests/Unit/PrestaShopBundle/EventListener/ContextEventListenerTestCase.php
@@ -34,6 +34,7 @@
 use PrestaShop\PrestaShop\Adapter\LegacyContext;
 use PrestaShop\PrestaShop\Adapter\Shop\Repository\ShopRepository;
 use PrestaShop\PrestaShop\Core\Domain\Shop\ValueObject\ShopId;
+use PrestaShop\PrestaShop\Core\FeatureFlag\FeatureFlagStateCheckerInterface;
 use ReflectionProperty;
 use Shop;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
@@ -82,6 +83,17 @@ protected function mockLegacyContext(array $cookieValues): LegacyContext|MockObj
         return $legacyContext;
     }
 
+    protected function mockFeatureFlagStateChecker(): FeatureFlagStateCheckerInterface|MockObject
+    {
+        $featureFlagStateChecker = $this->createMock(FeatureFlagStateCheckerInterface::class);
+        $featureFlagStateChecker
+            ->method('isEnabled')
+            ->willReturn(true)
+        ;
+
+        return $featureFlagStateChecker;
+    }
+
     protected function createRequestEvent(Request $request): RequestEvent
     {
         return new RequestEvent(static::createKernel(), $request, HttpKernelInterface::MAIN_REQUEST);