sshuser group


I have set up a user as the main admin user in my virtualmin, with no virtual server. All users are included to a group sshusers. The problem is the admin user keeps dropping the sshuser group. I will go to log in using Putty, sometimes it’s OK, sometimes i am denied access. When I then check my admin user’s group status, sshuser is not there. I re-include, all good till next time it happens. Seems random, and only this user. The common or garden variety users don’t have the problem. Any clues on how to make the group persist for this user?