diff --git a/COMET.Web.Common.Tests/Services/CacheService/CacheServiceTestFixture.cs b/COMET.Web.Common.Tests/Services/CacheService/CacheServiceTestFixture.cs
new file mode 100644
index 00000000..0c2cdb5d
--- /dev/null
+++ b/COMET.Web.Common.Tests/Services/CacheService/CacheServiceTestFixture.cs
@@ -0,0 +1,116 @@
+// --------------------------------------------------------------------------------------------------------------------
+//  <copyright file="CacheServiceTestFixture.cs" company="Starion Group S.A.">
+//    Copyright (c) 2023-2024 Starion Group S.A.
+// 
+//    Authors: Sam Gerené, Alex Vorobiev, Alexander van Delft, Jaime Bernar, Théate Antoine, Nabil Abbar
+// 
+//    This file is part of CDP4-COMET WEB Community Edition
+//    The CDP4-COMET WEB Community Edition is the Starion Web Application implementation of ECSS-E-TM-10-25
+//    Annex A and Annex C.
+// 
+//    Licensed under the Apache License, Version 2.0 (the "License");
+//    you may not use this file except in compliance with the License.
+//    You may obtain a copy of the License at
+// 
+//        http://www.apache.org/licenses/LICENSE-2.0
+// 
+//    Unless required by applicable law or agreed to in writing, software
+//    distributed under the License is distributed on an "AS IS" BASIS,
+//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//    See the License for the specific language governing permissions and
+//    limitations under the License.
+// 
+//  </copyright>
+//  --------------------------------------------------------------------------------------------------------------------
+
+
+namespace COMET.Web.Common.Tests.Services.CacheService
+{
+    using CDP4Common.EngineeringModelData;
+
+    using COMET.Web.Common.Enumerations;
+    using COMET.Web.Common.Services.Cache;
+
+    using NUnit.Framework;
+
+    [TestFixture]
+    public class CacheServiceTestFixture
+    {
+        private CacheService cacheService;
+
+        [SetUp]
+        public void Setup()
+        {
+            this.cacheService = new CacheService();
+        }
+
+        [Test]
+        public void VerifyAddNewKey()
+        {
+            var engineeringModel = new EngineeringModel();
+            var browserSessionSettingKey = BrowserSessionSettingKey.LastUsedEngineeringModel;
+
+            Assert.That(() => this.cacheService.AddOrUpdateBrowserSessionSetting(browserSessionSettingKey, engineeringModel), Throws.Nothing);
+
+            Assert.That(this.cacheService.TryGetBrowserSessionSetting(browserSessionSettingKey, out var result), Is.True);
+
+            Assert.That(result, Is.EqualTo(engineeringModel));
+        }
+
+        [Test]
+        public void VerifyKeyDoesNotExistWorksAsExpected()
+        {
+            var browserSessionSettingKey = BrowserSessionSettingKey.LastUsedEngineeringModel;
+
+            Assert.That(this.cacheService.TryGetBrowserSessionSetting(browserSessionSettingKey, out var result), Is.False);
+
+            Assert.That(result, Is.Null);
+        }
+
+        [Test]
+        public void VerifyOverwriteExistingKey()
+        {
+            var engineeringModel1 = new EngineeringModel();
+            var browserSessionSettingKey = BrowserSessionSettingKey.LastUsedEngineeringModel;
+
+            Assert.That(() => this.cacheService.AddOrUpdateBrowserSessionSetting(browserSessionSettingKey, engineeringModel1), Throws.Nothing);
+
+            Assert.That(this.cacheService.TryGetBrowserSessionSetting(browserSessionSettingKey, out var result), Is.True);
+
+            Assert.That(result, Is.EqualTo(engineeringModel1));
+
+            var engineeringModel2 = new EngineeringModel();
+
+            Assert.That(() => this.cacheService.AddOrUpdateBrowserSessionSetting(browserSessionSettingKey, engineeringModel2), Throws.Nothing);
+
+            Assert.That(this.cacheService.TryGetBrowserSessionSetting(browserSessionSettingKey, out var result2), Is.True);
+
+            Assert.That(result2, Is.EqualTo(engineeringModel2));
+        }
+
+        [Test]
+        public void VerifyGetOrAddKey()
+        {
+            var engineeringModel1 = new EngineeringModel();
+            var browserSessionSettingKey = BrowserSessionSettingKey.LastUsedEngineeringModel;
+
+            Assert.That(this.cacheService.TryGetOrAddBrowserSessionSetting(browserSessionSettingKey, engineeringModel1, out var result), Is.True);
+
+            Assert.That(result, Is.EqualTo(engineeringModel1));
+
+            Assert.That(this.cacheService.TryGetBrowserSessionSetting(browserSessionSettingKey, out var result2), Is.True);
+
+            Assert.That(result2, Is.EqualTo(engineeringModel1));
+
+            var engineeringModel2 = new EngineeringModel();
+
+            Assert.That(this.cacheService.TryGetOrAddBrowserSessionSetting(browserSessionSettingKey, engineeringModel2, out var result3), Is.True);
+
+            Assert.That(result3, Is.EqualTo(engineeringModel1));
+
+            Assert.That(this.cacheService.TryGetBrowserSessionSetting(browserSessionSettingKey, out var result4), Is.True);
+
+            Assert.That(result4, Is.EqualTo(engineeringModel1));
+        }
+    }
+}
diff --git a/COMET.Web.Common/Services/Cache/CacheService.cs b/COMET.Web.Common/Services/Cache/CacheService.cs
index ecf598e0..a56d38ad 100644
--- a/COMET.Web.Common/Services/Cache/CacheService.cs
+++ b/COMET.Web.Common/Services/Cache/CacheService.cs
@@ -63,12 +63,14 @@ public bool TryGetBrowserSessionSetting(BrowserSessionSettingKey browserSessionS
         /// <returns>true if the setting was found</returns>
         public bool TryGetOrAddBrowserSessionSetting(BrowserSessionSettingKey browserSessionSettingKeyKey, object defaultBrowserSessionSettingValue, out object browserSessionSettingvalue)
         {
-            if (this.browserSessionSettings.TryGetValue(browserSessionSettingKeyKey, out browserSessionSettingvalue))
+            if (!this.browserSessionSettings.TryGetValue(browserSessionSettingKeyKey, out browserSessionSettingvalue))
             {
-                return browserSessionSettingvalue != null;
+                this.AddOrUpdateBrowserSessionSetting(browserSessionSettingKeyKey, defaultBrowserSessionSettingValue);
+
+                this.browserSessionSettings.TryGetValue(browserSessionSettingKeyKey, out browserSessionSettingvalue);
             }
 
-            return false;
+            return browserSessionSettingvalue != null;
         }
 
         /// <summary>