Regimod usergroup not overriding permissions

[CoffeeLovesYou]

Hello.
I have a Regimod usergroup on my website which is basically if anyone is mis-behaving and a mod needs to watch them, all of their visitor messages/threads/posts are set for moderation approval. however, if they are in another member-usergroup such as a Teen Group that just allows them access to the Teen forum, or if they are in registered users for their user tag, or whatever the case may be, I set Regimod as the default usergroup and keep all of their usergroups set to how they were (also if they donated, i dont wanna take that tag away) but Regimod isn't over-riding the usergroups. All of the other usergroups have the same setting as registered users, but shouldn't Regimod be over-riding those permissions if it is in the Default Usergroup setting? We do not want our members to lose their tags when we need them on Regimod, and we have clan leaders who can approve members requests for usergroup join requests and they could accidentally add them back to the usergroup and mess it up. I have done this before without messing up any of their usergroups/tags but it isn't working now. Please tell me what I am doing wrong.