Clear All Notifications doesn't work for users created after setting custom default Notification events from Administration

STEPS TO REPRODUCE

1. Login as Admin (preferably on a fresh instance)
2. Go to Administer Wiki > Other > Notifications
3. Set some Pages Notifications to ON, menu and e-mail (e.g. for 'A new page is created' and 'A page is modified')
4. Create a new user (e.g. U1)
5. Create/update a page
6. Login with U1
7. Click on the Notifications bell > Clear All
8. Refresh the page

EXPECTED RESULTS

All event notifications are cleared, after refresh they are not displayed on the list anymore.

ACTUAL RESULTS

After refresh, the notifications are displayed back on the list (even after XWiki restart).

The issue reproduces also on XWiki 10.11.5 and 11.2.