Some local users from subwiki receive 3 mentions automatically after XWiki upgrade

STEPS TO REPRODUCE

1. Create fresh (older) instance of XWiki (e.g. 11.10.5)
2. Create a subwiki (e.g. with scope 'Both global and local users are available in the wiki')
3. Create 3 local users on subwiki (e.g. U1, U2,and U3)
4. Login with the user U1
5. Go to Notifications Settings and set all Pages to ON
6. Click on Notifications bell and make sure 'Watch this wiki' Notifications toggle is ON
7. Login with U2
8. Go to Notifications Settings and set all Pages to ON
9. Click on Notifications bell and make sure 'Watch this wiki' Notifications toggle is OFF
10. Close the instance
11. Go to the newer instance (e.g. 12.5.1) and copy/cut the

    [...]webapps\xwiki

    folder and replace it (first delete the old one) in the same location on the older version

12. Start XWiki and follow DW to the end
13. Run also the DW for the subwiki
14. On subwiki, login with U1, U2 and U3
15. Observe the notification list for each user

EXPECTED RESULTS

No mention events are displayed on users' notifications list, as they were not mentioned anywhere.

ACTUAL RESULTS

Both U1 (which had Pages ON, 'Watch this wiki' ON) and U3 (which had Pages OFF, 'Watch this wiki' OFF - default settings) received 3 mentions in their notifications list.

Those 3 mentions lead to:

http://localhost/xwiki/wiki/subwikiglobal/view/XWiki/Mentions/#mention-example-1
http://localhost/xwiki/wiki/subwikiglobal/view/XWiki/Mentions/#mention-example-2
http://localhost/xwiki/wiki/subwikiglobal/view/XWiki/Mentions/#mention-example-3

but the links are not accessible because the URLs are missing the port of the XWiki instance.

The user U2 (which had Pages ON, 'Watch this wiki' OFF) did not received the mentions.