User notification frequency not saved for usernames containing forbidden symbols

Prerequisites

Created programmatically user with username that includes not allowed symbols. For this you can use snippet

I used fullname XWiki.test.-.user.com, and in XWiki User Directory this is listed with username com

Steps to reproduce

1. Log in as an administrator.
2. Open the profile page of a created user.
3. Change any notification preference (for example, set Email frequency to Weekly).
4. Observe the success message “Saved”. changed email frequency.png
5. Refresh the user profile page.

Actual Result

The Email frequency value is reverted to the default setting (Daily) after the page refresh. preferences after refrshing user profile page.png

Expected Result

The Email frequency should remain set to the saved value (Weekly) after refreshing the page.