Global notification filters disappear after user creation

STEPS TO REPRODUCE

1. Login as Admin
2. Go to Administer Wiki > Social > Notifications
3. Add a custom filter, e.g.
   Location -> "Sandbox.TestPage1"
   Action -> Notify of the event
   Events type (Pages) -> A page is modified
   Channel -> Alert & Email
4. Create a user
5. Close and restart XWiki instance
6. Go to Administer Wiki > Social > Notifications

EXPECTED RESULTS

The global custom notification filter is still displayed in Administer Wiki > Social > Notifications.

ACTUAL RESULTS

The global custom filter is missing. As a result, new created users will not inherit the filter setting.

It is to be mentioned that this does not happen every time the server is restarted. Unfortunately, I couldn't discover a pattern to follow in order to reproduce the issue every time.

Reproduced on both Jetty 9.4.29 and Tomcat 9.0.45.