Notifications Watchlist feature doesn't work properly - selections are ignored

Steps to reproduce:

1. Enable the new watchlist feature for notifications from the xwiki.properties file
2. Log in as Admin
3. Create 4 simple users and 4 pages P1.P2.P3.P4
4. Log in as user 1 and go to P1 (the parent page)
5. Click on the bell > under Notifications > Watch this page
6. Log in as user 2 and go to P1 (the parent page)
7. Click on the bell > under Notifications > Watch this page and children
8. Log in as user 3 and go to P1 (the parent page)
9. Click on the bell > under Notifications > Watch this wiki
10. Log in as user 4
11. Make changes to the P1 page and the child page (create/update/delete/comments/attachments)
12. Make changes to other pages of the wiki eg. Sandbox, Home
13. Log in with users 1-3 and see the Notifications received

Expected results: User 1 receives notifications only for page P1, user 2 for P1 and child pages and user 3 for all changes in the wiki.

Actual results: All 3 users receive notifications about all the changes done in the wiki.