If the users are using the following URLs to access the instance:
then the instance becomes inaccessible when they use any AppBar links. By pressing on any links from AppBar, the browser URL is transformed to "http://localhost:8080 ..." but that URL is inaccessible (ERR_CONNECTION_REFUSED).
Without the AppBar, users are unable to navigate to their applications or install new extensions. This bug manifested in an usability session and the user's experience was critically affected.