diff --git a/core/modules/media_library/src/Form/AddFormBase.php b/core/modules/media_library/src/Form/AddFormBase.php
index c4f4452828..b872493a50 100644
--- a/core/modules/media_library/src/Form/AddFormBase.php
+++ b/core/modules/media_library/src/Form/AddFormBase.php
@@ -405,8 +405,8 @@ public function removeButtonSubmit(array $form, FormStateInterface $form_state)
     // Update the list of added media items in the form state.
     unset($added_media[$delta]);
 
-    // Re-key the media items before setting them in the form state.
-    $form_state->set('media', array_values($added_media))->setRebuild();
+    // Update the media items in the form state.
+    $form_state->set('media', $added_media)->setRebuild();
 
     // Show a message to the user to confirm the media is removed.
     $this->messenger()->addStatus($this->t('The media item %label has been removed.', ['%label' => $removed_media->label()]));
@@ -449,20 +449,24 @@ public function updateFormCallback(array &$form, FormStateInterface $form_state)
         $response->addCommand(new InvokeCommand('#media-library-add-form-wrapper :tabbable', 'focus'));
       }
       // When there are still more items, update the form and shift the focus to
-      // the next media item. This is technically the item with the same delta
-      // as the one that has been removed. If the last list item is removed,
-      // shift focus to the previous item.
+      // the next media item. If the last list item is removed, shift focus to
+      // the previous item.
       else {
         $response->addCommand(new ReplaceCommand("#$wrapper_id", $form));
 
-        // We need to add 1 to the delta to shift focus to the next item,
-        // because the 'nth-child' selector starts counting with 1 and the delta
-        // starts with 0.
-        $delta = array_slice($triggering_element['#array_parents'], -2, 1)[0];
-        if (isset($added_media[$delta])) {
-          $delta++;
+        // Try to find the sequence number of the next media item for use in the
+        // nth-child selector by checking if the delta is bigger than the
+        // removed delta. If there is no item with a bigger delta, we
+        // automatically use the sequence number of the previous item.
+        $removed_delta = array_slice($triggering_element['#array_parents'], -2, 1)[0];
+        $nth_child = 0;
+        foreach ($added_media as $delta => $media) {
+          $nth_child++;
+          if ($delta > $removed_delta) {
+            break;
+          }
         }
-        $response->addCommand(new InvokeCommand(".media-library-add-form__media:nth-child($delta)", 'focus'));
+        $response->addCommand(new InvokeCommand(".media-library-add-form__media:nth-child($nth_child)", 'focus'));
       }
     }
     // Update the form and shift focus to the added media items.
diff --git a/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
index 7fbc75b2ce..312dbb9330 100644
--- a/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
+++ b/core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTest.php
@@ -597,6 +597,7 @@ public function testWidgetAnonymous() {
   public function testWidgetUpload() {
     $assert_session = $this->assertSession();
     $page = $this->getSession()->getPage();
+    $driver = $this->getSession()->getDriver();
 
     foreach ($this->getTestFiles('image') as $image) {
       $extension = pathinfo($image->filename, PATHINFO_EXTENSION);
@@ -735,11 +736,6 @@ public function testWidgetUpload() {
     // Select a media item.
     $page->find('css', '.media-library-view .js-click-to-select-checkbox input')->click();
     $assert_session->pageTextContains('1 item selected');
-
-    // Multiple uploads should be allowed.
-    // @todo Add test when https://github.com/minkphp/Mink/issues/358 is closed
-    $this->assertTrue($assert_session->fieldExists('Add files')->hasAttribute('multiple'));
-
     $page->attachFileToField('Add files', $this->container->get('file_system')->realpath($png_image->uri));
     $assert_session->assertWaitOnAjaxRequest();
     $page->fillField('Name', 'Unlimited Cardinality Image');
@@ -848,6 +844,59 @@ public function testWidgetUpload() {
     $this->assertJsCondition('jQuery("#media-library-add-form-wrapper :tabbable").is(":focus")');
     $assert_session->elementNotExists('css', '.media-library-add-form__fields');
     $assert_session->elementExists('css', '.media-library-menu');
+    $page->find('css', '.ui-dialog-titlebar-close')->click();
+
+    // Assert uploading multiple files.
+    $assert_session->elementExists('css', '.media-library-open-button[name^="field_unlimited_media"]')->click();
+    $assert_session->assertWaitOnAjaxRequest();
+    $assert_session->pageTextContains('Add or select media');
+    $page->clickLink('Type Three');
+    $assert_session->assertWaitOnAjaxRequest();
+    $this->assertTrue($assert_session->fieldExists('Add files')->hasAttribute('multiple'));
+    // Create a list of new files to upload.
+    $filenames = [];
+    $remote_paths = [];
+    foreach(range(1, 3) as $i) {
+      $path = $file_system->copy($png_image->uri);
+      $filenames[] = $file_system->basename($path);
+      $remote_paths[] = $driver->uploadFileAndGetRemoteFilePath($file_system->realpath($path));
+    }
+    $page->findField('Add files')->setValue(implode("\n", $remote_paths));
+    $assert_session->assertWaitOnAjaxRequest();
+    // Assert the media item fields are shown and the vertical tabs are no
+    // longer shown.
+    $assert_session->elementExists('css', '.media-library-add-form__fields');
+    $assert_session->elementNotExists('css', '.media-library-menu');
+    // Assert all files have been added.
+    $assert_session->fieldValueEquals('media[0][fields][name][0][value]', $filenames[0]);
+    $assert_session->fieldValueEquals('media[1][fields][name][0][value]', $filenames[1]);
+    $assert_session->fieldValueEquals('media[2][fields][name][0][value]', $filenames[2]);
+    // Set alt texts.
+    $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]);
+    $page->fillField('media[2][fields][field_media_test_image][0][alt]', $filenames[2]);
+    // 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');
+    $this->assertJsCondition('jQuery(".media-library-add-form__media:nth-child(2)").is(":focus")');
+    $assert_session->pageTextContains('The media item ' . $filenames[1] . ' has been removed.');
+    $assert_session->fieldValueEquals('media[0][fields][name][0][value]', $filenames[0]);
+    $assert_session->fieldValueEquals('media[0][fields][field_media_test_image][0][alt]', $filenames[0]);
+    $assert_session->fieldNotExists('media[1][fields][name][0][value]');
+    $assert_session->fieldNotExists('media[1][fields][field_media_test_image][0][alt]');
+    $assert_session->fieldValueEquals('media[2][fields][name][0][value]', $filenames[2]);
+    $assert_session->fieldValueEquals('media[2][fields][field_media_test_image][0][alt]', $filenames[2]);
+    // Remove the last file and assert the focus is shifted to the container
+    // of the first media item and field values are still correct.
+    $page->pressButton('media-2-remove-button');
+    $this->assertJsCondition('jQuery(".media-library-add-form__media:nth-child(1)").is(":focus")');
+    $assert_session->pageTextContains('The media item ' . $filenames[2] . ' has been removed.');
+    $assert_session->fieldValueEquals('media[0][fields][name][0][value]', $filenames[0]);
+    $assert_session->fieldValueEquals('media[0][fields][field_media_test_image][0][alt]', $filenames[0]);
+    $assert_session->fieldNotExists('media[1][fields][name][0][value]');
+    $assert_session->fieldNotExists('media[1][fields][field_media_test_image][0][alt]');
+    $assert_session->fieldNotExists('media[2][fields][name][0][value]');
+    $assert_session->fieldNotExists('media[2][fields][field_media_test_image][0][alt]');
   }
 
   /**