Results bar keeps loading in 'Filters' lightbox

STEPS TO REPRODUCE

1. Click on the Watchlist bell
2. Click on Settings, in the right side of Notifications
3. In the Notifications Preferences set Notifications to ON (e.g. for System, Notification menu)
4. Click on a Filters Button

EXPECTED RESULTS

The Filters lightbox opens and the current set filters are shown. The user can select how many results per page should be displayed.

ACTUAL RESULTS

The Filters lightbox opens, but the filter results bar keeps loading until selecting another value (e.g. 20) from the drop-down list or delete a filter. The issue is not reproducing after setting a filter in current session and clicking again on the respective Filters Button. However, after restarting the XWiki instance and click on a Filters Button for an event which had filters already set, the bar keeps loading indefinitely.