diff --git a/core/modules/media_library/css/media_library.theme.css b/core/modules/media_library/css/media_library.theme.css
index 316e924623..1b00001d42 100644
--- a/core/modules/media_library/css/media_library.theme.css
+++ b/core/modules/media_library/css/media_library.theme.css
@@ -356,6 +356,11 @@
   background-position: left 0;
 }
 
+.media-library-add-form .media-library-add-form__remove-button:focus {
+  color: #787878;
+  border: 0;
+}
+
 .media-library-add-form .media-library-add-form__remove-button:hover {
   color: #e00;
   border: 0;
diff --git a/core/modules/media_library/src/Form/AddFormBase.php b/core/modules/media_library/src/Form/AddFormBase.php
index e58907f489..4df0fc314e 100644
--- a/core/modules/media_library/src/Form/AddFormBase.php
+++ b/core/modules/media_library/src/Form/AddFormBase.php
@@ -179,6 +179,9 @@ public function buildForm(array $form, FormStateInterface $form_state) {
    *   The element containing the required fields sub-form.
    */
   protected function buildEntityFormElement(MediaInterface $media, array $form, FormStateInterface $form_state, $delta) {
+    // We need to make sure each button has a unique name attribute. The default
+    // name for button elements is 'op'. If the name is not unique, the
+    // triggering element is not set correctly.
     $parents = $form['#parents'];
     $id_suffix = $parents ? '-' . implode('-', $parents) : '';
 
@@ -355,8 +358,7 @@ public function removeButtonSubmit(array $form, FormStateInterface $form_state)
     // Retrieve the delta of the media items from the parents of the remove
     // button.
     $triggering_element = $form_state->getTriggeringElement();
-    $delta_slice = array_slice($triggering_element['#array_parents'], -2, 1);
-    $delta = reset($delta_slice);
+    $delta = array_slice($triggering_element['#array_parents'], -2, 1)[0];
     // Update the list of added media items from the form state.
     $added_media = $form_state->get('media');
     unset($added_media[$delta]);