diff -u b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php
--- b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php
+++ b/core/modules/views_ui/tests/src/FunctionalJavascript/FilterOptionsTest.php
@@ -55,7 +55,9 @@
     });
     $this->assertTrue($page->findField('name[views.views_test_field_1]')->isVisible());
     $this->assertFalse($page->findField('name[views.views_test_field_2]')->isVisible());
-    $session->wait(1000, 'jQuery("#drupal-live-announce").html().indexOf("1 option is available in the modified list.") > -1');
+
+    // Check that the new number of rows is set by announce.
+    $session->wait(10000, 'jQuery("#drupal-live-announce").html().indexOf("1 option is available in the modified list.") > -1');
     $web_assert->elementTextContains('css', '#drupal-live-announce', '1 option is available in the modified list.');
 
     // Test the ".description" field in search.
@@ -73,6 +75,13 @@
     });
     $this->assertFalse($page->findField('name[views.views_test_field_2]')->isVisible());
     $this->assertFalse($page->findField('name[views.views_test_field_1]')->isVisible());
+
+    // Clear the search and see if the new number of rows is set by announce.
+    $options_search->setValue('');
+    $block_rows = $page->findAll('css', 'tr.filterable-option');
+    $block_row_count = count($block_rows);
+    $session->wait(10000, 'jQuery("#drupal-live-announce").html().indexOf("' . $block_row_count . ' options are available") > -1');
+    $web_assert->elementTextContains('css', '#drupal-live-announce', $block_row_count . ' options are available in the modified list.');
   }
 
 }