We use the feature that automatically allocates users to groups via their email domain. We had a partner of ours with about 20 users that needed a change in their group allocation. Instead of “Partner” we changed them to "Prospect:. Meaning they went from full access to limited access. We thought we could do this by just removing their domain from the “Partner” Group and adding it to the “Prospect” Group. This however did not work. We instead had to open the admin panel on each profile and delete the “Partner” grouping from it. This seems like a bug to me. The list of email domains should control who can see the content assigned to that group.