Issue #3201274 by douggreen: Cache tags are not set properly

src/Plugin/Block/SmartMenusBlock.php

@@ -249,12 +249,14 @@ class SmartMenusBlock extends BlockBase implements ContainerFactoryPluginInterfa
       ],
       '#menu_name' => $menu_name,
       '#toggle' => $toggle,
-      '#cache' => [
-        'contexts' => ['url.path'],
-      ],
     ];
 
     $build['#menu_tree'] = $this->renderer->renderPlain($rendered_menu);
+    $build['#cache'] = [
+      'contexts' => ['url.path'],
+      'tags' => $tree['#cache']['tags'],
+    ];
+
     return $build;
   }
 }