Validated XF Owner
I’ll try to replicate it as soon as I get a chance.
Unregistered and registered are set to "no". I have my premium members set to yes. Other than the one member, nobody that wasn't in the premium usergroup could access the groups. As for the rest, once their premium membership expires, they are keeping access to the group they are in.
Contact @TickTackk on XenForo. I got a mod created from him where it will associate the Social Group with a Usergroup. You can add/remove from either. Therefore, you can tie your premium membership to a usergroup and the member would be added to both. And vice versa if the premium membership removes the member from the Usergroup, it would removed the member from the Social Group. If you do, tell him I referred you.