The Side-effects of Using Address Book Policies to Limit Teams Search
You can use Exchange Address Book Policies (ABPs) to limit the ability of Teams users to chat with each other. Everything works as expected until you look for some new teams to join only to find that Teams can’t suggest any teams to you. The problem seems to be with filtering the set of teams returned by the Microsoft Graph to take account of the scope applied to the user. At least, that’s what I think is going on.