diff --git a/Classes/Xclass/ContainerPreviewRenderer.php b/Classes/Xclass/ContainerPreviewRenderer.php
index 2d4b5d1..9f72d39 100644
--- a/Classes/Xclass/ContainerPreviewRenderer.php
+++ b/Classes/Xclass/ContainerPreviewRenderer.php
@@ -120,7 +120,7 @@ public function renderPageModulePreviewContent(GridColumnItem $item): string
     protected function getColumnCollapsedState(int $recordUid, int $colPos, array $col): bool
     {
         $collapseId = $recordUid . ContainerGridColumn::CONTAINER_COL_POS_DELIMITER_V12 . $colPos;
-        if ($this->getBackendUser()->uc['moduleData']['list']['containerExpanded'][$collapseId] ?? false) {
+        if (isset($this->getBackendUser()->uc['moduleData']['list']['containerExpanded'][$collapseId])) {
             $collapsed = $this->getBackendUser()->uc['moduleData']['list']['containerExpanded'][$collapseId] > 0;
         } else {
             $collapsed = (bool)($col['collapsed'] ?? false);