diff --git a/core/modules/media_library/src/MediaLibraryState.php b/core/modules/media_library/src/MediaLibraryState.php
index 5badb051cd..7a0a4f6363 100644
--- a/core/modules/media_library/src/MediaLibraryState.php
+++ b/core/modules/media_library/src/MediaLibraryState.php
@@ -86,7 +86,11 @@ public function __construct(array $parameters = []) {
    * @return static
    *   A state object.
    */
-  public static function create($opener_id, array $allowed_media_type_ids, $selected_type_id, $remaining_slots, array $opener_parameters = [], string $form_mode = self::DEFAULT_FORM_MODE) {
+  public static function create($opener_id, array $allowed_media_type_ids, $selected_type_id, $remaining_slots, array $opener_parameters = [], ?string $form_mode = self::DEFAULT_FORM_MODE) {
+    // When form_mode is passed explicitly as null, defaulting doesn't happen:
+    if (is_null($form_mode)) {
+      $form_mode = self::DEFAULT_FORM_MODE;
+    }
     $state = new static([
       'media_library_opener_id' => $opener_id,
       'media_library_allowed_types' => $allowed_media_type_ids,
@@ -156,7 +160,11 @@ public static function fromRequest(Request $request) {
    *   If one of the passed arguments is missing or does not pass the
    *   validation.
    */
-  protected function validateRequiredParameters($opener_id, array $allowed_media_type_ids, $selected_type_id, $remaining_slots, string $form_mode = self::DEFAULT_FORM_MODE) {
+  protected function validateRequiredParameters($opener_id, array $allowed_media_type_ids, $selected_type_id, $remaining_slots, ?string $form_mode = self::DEFAULT_FORM_MODE) {
+    // When form_mode is passed explicitly as null, defaulting doesn't happen:
+    if (is_null($form_mode)) {
+      $form_mode = self::DEFAULT_FORM_MODE;
+    }
     // The opener ID must be a non-empty string.
     if (!is_string($opener_id) || empty(trim($opener_id))) {
       throw new \InvalidArgumentException('The opener ID parameter is required and must be a string.');
diff --git a/core/modules/media_library/src/Plugin/Field/FieldWidget/MediaLibraryWidget.php b/core/modules/media_library/src/Plugin/Field/FieldWidget/MediaLibraryWidget.php
index 46bd97d80c..1394543b8c 100644
--- a/core/modules/media_library/src/Plugin/Field/FieldWidget/MediaLibraryWidget.php
+++ b/core/modules/media_library/src/Plugin/Field/FieldWidget/MediaLibraryWidget.php
@@ -285,6 +285,7 @@ public static function setMediaTypesValue(array &$element, $input, FormStateInte
    */
   public function settingsSummary() {
     $summary = [];
+    $media_type_labels = [];
 
     $form_modes = $this->entityDisplayRepository->getFormModeOptions('media');
     $mode = $this->getSetting('form_mode');
@@ -292,13 +293,11 @@ public function settingsSummary() {
 
     $media_types = $this->entityTypeManager->getStorage('media_type')->loadMultiple($this->getAllowedMediaTypeIdsSorted());
     if (count($media_types) !== 1) {
-      $media_type_labels = [];
       foreach ($media_types as $media_type) {
         $media_type_labels[] = $media_type->label();
       }
       $summary[] = $this->t('Tab order: @order', ['@order' => implode(', ', $media_type_labels)]);
     }
-
     return $summary;
   }