A Flag Plus banner does not update without a page reload (does not use AJAX refresh) if you change a Flag state using a Flag link.

Because Flag uses its own variation on old pre-Drupal7 AJAX, it's not easy to refresh a Flag Plus banner using AJAX if you change a Flag state using a Flag link. For now use the option when creating or editing a flag to NOT use AJAX (to instead use full page refresh) in Flag toggle links.

Visit also #2403131: HOWTO reload a node from hook_flag_flag/unflag without disrupting flag AJAX links (and without custom JavaScript if possible).