diff --git a/src/Controller/Admin/DataObject/ClassController.php b/src/Controller/Admin/DataObject/ClassController.php
index 0ee08ad..0168e4f 100644
--- a/src/Controller/Admin/DataObject/ClassController.php
+++ b/src/Controller/Admin/DataObject/ClassController.php
@@ -861,7 +861,9 @@ public function fieldcollectionTreeAction(Request $request, EventDispatcherInter
             }
         }
 
-        $definitions = $groups;
+        foreach ($groups as $group) {
+            $definitions[] = $group;
+        }
 
         $event = new GenericEvent($this, [
             'list' => $definitions,
@@ -1247,7 +1249,9 @@ public function objectbrickTreeAction(Request $request, EventDispatcherInterface
             }
         }
 
-        $definitions = $groups;
+        foreach ($groups as $group) {
+            $definitions[] = $group;
+        }
 
         $event = new GenericEvent($this, [
             'list' => $definitions,
diff --git a/src/Controller/Admin/SettingsController.php b/src/Controller/Admin/SettingsController.php
index 5ec90ae..25aed8f 100644
--- a/src/Controller/Admin/SettingsController.php
+++ b/src/Controller/Admin/SettingsController.php
@@ -744,7 +744,9 @@ public function thumbnailTreeAction(): JsonResponse
             }
         }
 
-        $thumbnails = $groups;
+        foreach ($groups as $group) {
+            $thumbnails[] = $group;
+        }
 
         return $this->adminJson($thumbnails);
     }
@@ -928,7 +930,9 @@ public function videoThumbnailTreeAction(): JsonResponse
             }
         }
 
-        $thumbnails = $groups;
+        foreach ($groups as $group) {
+            $thumbnails[] = $group;
+        }
 
         return $this->adminJson($thumbnails);
     }