Issue #3317378 by Spokje, Wim Leers: [random test failure]...

Issue #3317378 by Spokje, Wim Leers: [random test failure] DrupalTestsmedia_libraryFunctionalJavascriptWidgetViewsTest::testWidgetViews random fail

core/modules/media_library/tests/src/FunctionalJavascript/MediaLibraryTestBase.php

@@ -428,6 +428,7 @@ protected function switchToMediaLibraryTable() {
    * Asserts that the grid display of the widget view is visible.
    */
   protected function assertMediaLibraryGrid() {
+    $this->assertSession()->assertWaitOnAjaxRequest();
     $this->assertSession()
       ->elementExists('css', '.js-media-library-view[data-view-display-id="widget"]');
   }

core/modules/media_library/tests/src/FunctionalJavascript/WidgetViewsTest.php

@@ -117,8 +117,9 @@ public function testWidgetViews() {
     // Assert the exposed filters can be applied.
     $page->fillField('Name', 'Dog');
     $page->pressButton('Apply filters');
-    $this->waitForText('Dog');
-    $this->waitForNoText('Crocodile');
+    $assert_session->assertWaitOnAjaxRequest();
+    $assert_session->pageTextContains('Dog');
+    $assert_session->pageTextNotContains('Crocodile');
     $assert_session->pageTextNotContains('Turtle');
     $page->checkField('Select Dog');
     $assert_session->linkExists('Table');