Old users in License Manager

I am finding old users in license manager. I highlight the user, click delete in the drop down menu under license and delete the user.

Most of the users have been removed from USER MANAGER.

Why do they continue to re-appear in LICENSE MANAGER? Is there somewhere else where they must be removed ? What is triggering their re-appearance ?

Sincerely,

Barry
mckinley.ba@rittal.ca