diff --git a/core/modules/media_library/src/Form/FileUploadForm.php b/core/modules/media_library/src/Form/FileUploadForm.php
index ec7362fc63..81367821c2 100644
--- a/core/modules/media_library/src/Form/FileUploadForm.php
+++ b/core/modules/media_library/src/Form/FileUploadForm.php
@@ -320,9 +320,8 @@ public function removeButtonSubmit(array $form, FormStateInterface $form_state)
     $triggering_element = $form_state->getTriggeringElement();
     $delta = array_slice($triggering_element['#array_parents'], -2, 1)[0];
 
-    /** @var \Drupal\media\MediaInterface[] $added_media */
-    $added_media = $form_state->get('media');
-    $removed_media = $added_media[$delta];
+    /** @var \Drupal\media\MediaInterface $removed_media */
+    $removed_media = $form_state->get(['media', $delta]);
 
     $file = $removed_media->get($this->getSourceFieldName($removed_media->bundle->entity))->entity;
     if ($file instanceof FileInterface && empty($this->fileUsage->listUsage($file))) {
diff --git a/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
index 261f29c1f3..a088e87678 100644
--- a/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
+++ b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
@@ -1114,21 +1114,21 @@ public function testWidgetUpload() {
     $assert_session->pageTextContains('1 of 2 items selected');
     $assert_session->hiddenFieldValueEquals('current_selection', $added_media->id());
     // Ensure the created item is added in the widget.
+    $this->assertNotEmpty($assert_session->waitForText('Add or select media'));
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Insert selected');
     $this->assertNotEmpty($assert_session->waitForText('Added one media item.'));
-    $assert_session->assertWaitOnAjaxRequest();
     $assert_session->pageTextNotContains('Add or select media');
     $assert_session->pageTextContains($png_image->filename);
 
     // Remove the item.
     $assert_session->elementExists('css', '.media-library-item__remove')->click();
-    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertNotEmpty($assert_session->waitForElementRemoved('css', '.media-library-item'));
     $assert_session->pageTextNotContains($png_image->filename);
 
     // Assert we can also directly insert uploaded files in the widget.
     $assert_session->elementExists('css', '.media-library-open-button[name^="field_twin_media"]')->click();
     $assert_session->assertWaitOnAjaxRequest();
-    $assert_session->pageTextContains('Add or select media');
+    $this->assertNotEmpty($assert_session->waitForText('Add or select media'));
     $page->clickLink('Type Three');
     $assert_session->assertWaitOnAjaxRequest();
     $png_uri_2 = $file_system->copy($png_image->uri, 'public://');
@@ -1163,16 +1163,15 @@ public function testWidgetUpload() {
     $page->fillField('Name', 'Unlimited Cardinality Image');
     $page->fillField('Alternative text', $this->randomString());
     $assert_session->elementExists('css', '.ui-dialog-buttonpane')->pressButton('Save and select');
-    $assert_session->assertWaitOnAjaxRequest();
+    // Ensure the media item was saved to the library and automatically
+    // selected. The added media items should be in the first position of the
+    // add form.
     // Load the created media item.
+    $this->assertNotEmpty($assert_session->waitForText('Add or select media'));
+    $this->assertNotEmpty($assert_session->waitForText('Unlimited Cardinality Image'));
     $media_items = Media::loadMultiple();
     $added_media = array_pop($media_items);
     $added_media_name = $added_media->label();
-    // Ensure the media item was saved to the library and automatically
-    // selected. The added media items should be in the first position of the
-    // add form.
-    $assert_session->pageTextContains('Add or select media');
-    $assert_session->pageTextContains('Unlimited Cardinality Image');
     $assert_session->fieldValueEquals('media_library_select_form[0]', $added_media->id());
     $assert_session->checkboxChecked('media_library_select_form[0]');
     // Assert the item that was selected before uploading the file is still
@@ -1256,7 +1255,8 @@ public function testWidgetUpload() {
     // Assert the pre-selected items are shown.
     $selection_area = $assert_session->elementExists('css', '.media-library-add-form__selected-media');
     $assert_session->elementExists('css', 'summary', $selection_area)->click();
-    $assert_session->checkboxChecked("Select $existing_media_name", $selection_area);
+    $this->assertNotEmpty($checkbox = $assert_session->waitForField("Select $existing_media_name"));
+    $this->assertTrue($checkbox->isChecked());
     $page->uncheckField("Select $existing_media_name");
     $page->fillField('Alternative text', $this->randomString());
     $assert_session->hiddenFieldValueEquals('current_selection', '');
@@ -1346,7 +1346,9 @@ public function testWidgetUpload() {
     $page->fillField('media[0][fields][field_media_test_image][0][alt]', $filenames[0]);
     $page->fillField('media[1][fields][field_media_test_image][0][alt]', $filenames[1]);
     // Assert the file is available in the file storage.
-    $this->assertCount(1, $file_storage->loadByProperties(['filename' => $filenames[1]]));
+    $files = $file_storage->loadByProperties(['filename' => $filenames[1]]);
+    $this->assertCount(1, $files);
+    $file_1_uri = reset($files)->getFileUri();
     // Remove the second file and assert the focus is shifted to the container
     // of the next media item and field values are still correct.
     $page->pressButton('media-1-remove-button');
@@ -1354,9 +1356,10 @@ public function testWidgetUpload() {
     $assert_session->pageTextContains('The media item ' . $filenames[1] . ' has been removed.');
     // Assert the file was deleted.
     $this->assertEmpty($file_storage->loadByProperties(['filename' => $filenames[1]]));
+    $this->assertFileNotExists($file_1_uri);
 
     // When a file is already in usage, it should not be deleted. To test,
-    // let's add a usage for the fourth file (now in the third position).
+    // let's add a usage for $filenames[3] (now in the third position).
     $files = $file_storage->loadByProperties(['filename' => $filenames[3]]);
     $target_file = reset($files);
     $this->assertCount(1, $files);
@@ -1364,18 +1367,15 @@ public function testWidgetUpload() {
       'bundle' => 'type_three',
       'name' => 'Disturbing',
       'field_media_test_image' => [
-        [
-          'target_id' => $target_file->id(),
-          'alt' => 'I find your lack of faith disturbing.',
-        ],
+        ['target_id' => $target_file->id()],
       ],
     ])->save();
-    // Remove the fourth file (now in the third position) and assert the focus
-    // is shifted to the container of the previous media item and field values
-    // are still correct.
+    // Remove $filenames[3] (now in the third position) and assert the focus is
+    // shifted to the container of the previous media item and field values are
+    // still correct.
     $page->pressButton('media-3-remove-button');
-    $this->assertJsCondition('jQuery(".media-library-add-form__media[data-media-library-added-delta=2]").is(":focus")');
     $this->assertTrue($assert_session->waitForText('The media item ' . $filenames[3] . ' has been removed.'));
+    $this->assertJsCondition('jQuery(".media-library-add-form__media[data-media-library-added-delta=2]").is(":focus")');
     // Assert the file was not deleted, due to being in use elsewhere.
     $this->assertNotEmpty($file_storage->loadByProperties(['filename' => $filenames[3]]));
     $this->assertFileExists($target_file->getFileUri());