diff -u b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
--- b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
+++ b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
@@ -131,5 +131,4 @@
     $ajax_page_state = $request->get('ajax_page_state');
 
-
     // Aggregate CSS/JS if necessary, but only during normal site operation.
     $optimize_css = !defined('MAINTENANCE_MODE') && $this->config->get('css.preprocess');
diff -u b/core/misc/ajax.es6.js b/core/misc/ajax.es6.js
--- b/core/misc/ajax.es6.js
+++ b/core/misc/ajax.es6.js
@@ -563,12 +563,12 @@
         }
       },
       dataType: 'json',
-      type: ajax.type
+      type: 'POST',
     };
       },
       dataType: 'json',
       jsonp: false,
-      type: 'POST',
+      type: ajax.type,
     };
 
     if (elementSettings.dialog) {
@@ -1234,7 +1234,7 @@
       let $newContent = $($.parseHTML(response.data, document, true));
       // For backward compatibility, in some cases a wrapper will be added. This
       // behavior will be removed before Drupal 9.0.0. If different behavior is
-      // needed, the theme functions can be overriden.
+      // needed, the theme functions can be overridden.
       // @see https://www.drupal.org/node/2940704
       $newContent = Drupal.theme(
         'ajaxWrapperNewContent',