diff --git a/core/modules/outside_in/src/OffCanvasFormDialogTrait.php b/core/modules/outside_in/src/OffCanvasFormDialogTrait.php
index e265a8cb1c..af5beece23 100644
--- a/core/modules/outside_in/src/OffCanvasFormDialogTrait.php
+++ b/core/modules/outside_in/src/OffCanvasFormDialogTrait.php
@@ -74,8 +74,7 @@ protected function buildFormDialog(array &$form, FormStateInterface $form_state)
 
     if ($ajax_callback_added) {
       $form['#attached']['library'][] = 'core/drupal.dialog.ajax';
-      $form['#prefix'] = '<div id="off-canvas-form">';
-      $form['#suffix'] = '</div>';
+      $form['#attributes']['id'] = 'off-canvas-form';
     }
   }
 
@@ -94,7 +93,6 @@ protected function buildFormDialog(array &$form, FormStateInterface $form_state)
   public function submitFormDialog(array &$form, FormStateInterface $form_state) {
     $response = new AjaxResponse();
     if ($form_state->hasAnyErrors()) {
-      unset($form['#prefix'], $form['#suffix']);
       $form['status_messages'] = [
         '#type' => 'status_messages',
         '#weight' => -1000,
@@ -169,6 +167,9 @@ protected function getDestinationUrl() {
   /**
    * Get the redirect destination path if specified in request.
    *
+   * \Drupal\Core\Routing\RedirectDestination::get() cannot be used directly
+   * because it will use <current> if 'destination' is not in the query string.
+   *
    * @return string|null
    *   The redirect path or NULL if it is not specified.
    */
diff --git a/core/modules/outside_in/tests/src/FunctionalJavascript/OutsideInBlockFormTest.php b/core/modules/outside_in/tests/src/FunctionalJavascript/OutsideInBlockFormTest.php
index ff5ba1f29b..f9a5045889 100644
--- a/core/modules/outside_in/tests/src/FunctionalJavascript/OutsideInBlockFormTest.php
+++ b/core/modules/outside_in/tests/src/FunctionalJavascript/OutsideInBlockFormTest.php
@@ -108,9 +108,6 @@ public function testBlocks($block_plugin, $new_page_text, $element_selector, $la
         // Make sure the changes are present.
         $new_page_text_locator = "$block_selector $label_selector:contains($new_page_text)";
         $this->assertElementVisibleAfterWait('css', $new_page_text_locator);
-        // After the new page text is on the page wait to make sure all Ajax
-        // request are completed on the new page.
-        $web_assert->assertWaitOnAjaxRequest();
       }
 
       $this->openBlockForm($block_selector);
@@ -124,7 +121,7 @@ public function testBlocks($block_plugin, $new_page_text, $element_selector, $la
       // Open block form by clicking a element inside the block.
       // This confirms that default action for links and form elements is
       // suppressed.
-      $this->openBlockForm("$block_selector {$element_selector}");
+      $this->openBlockForm("$block_selector {$element_selector}", $block_selector);
       $web_assert->elementTextContains('css', '.contextual-toolbar-tab button', 'Editing');
       $web_assert->elementAttributeContains('css', '.dialog-off-canvas__main-canvas', 'class', 'js-outside-in-edit-mode');
       // Simulate press the Escape key.
@@ -209,8 +206,20 @@ protected function assertOffCanvasBlockFormIsValid() {
    *
    * @param string $block_selector
    *   A css selector selects the block or an element within it.
+   * @param string $contextual_link_container
+   *   The element that contains the contextual links. If none provide the
+   *   $block_selector will be used.
    */
-  protected function openBlockForm($block_selector) {
+  protected function openBlockForm($block_selector, $contextual_link_container = '') {
+    if (!$contextual_link_container) {
+      $contextual_link_container = $block_selector;
+    }
+    // Ensure that contextual link element is present because this is required
+    // to open the off-canvas dialog in edit mode.
+    $contextual_link = $this->assertSession()->waitForElement('css', "$contextual_link_container .contextual-links a");
+    $this->assertNotEmpty($contextual_link);
+    // Ensure that all other Ajax activity is completed.
+    $this->assertSession()->assertWaitOnAjaxRequest();
     $this->waitForToolbarToLoad();
     $this->click($block_selector);
     $this->waitForOffCanvasToOpen();