diff --git a/core/lib/Drupal/Core/Menu/MenuTreeStorage.php b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
index 858ca60..c50f7b4 100644
--- a/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
+++ b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
@@ -299,7 +299,12 @@ protected function doSave(array $link) {
       $affected_menus[$original['menu_name']] = $original['menu_name'];
       $fields = $this->preSave($link, $original);
       // If $link matches the $original data then exit early as there are no
-      // changes to make. Note that $fields will not contain the mlid key.
+      // changes to make. Use array_diff_assoc() to check if they match because:
+      // - Some of the data types of the values are not the same. The values
+      //   in $original are all strings because they have come from database but
+      //   $fields contains typed values.
+      // - MenuTreeStorage::preSave() removes the 'mlid' from $fields.
+      // - The order of the keys in $original and $fields is different.
       if (array_diff_assoc($fields, $original) == [] && array_diff_assoc($original, $fields) == ['mlid' => $link['mlid']]) {
         return $affected_menus;
       }