There is so much goofiness happening in those web portals (and also the New Portal, and the Legacy Portal) that issues like this don’t surprise me. Every time I click a button in there I worry that the wrong thing will happen to a different object. Sometimes the display reflects the worst possible outcome, like adding a user to a group will show you the new group membership as just containing that 1 new user and nobody else. Quite a few moments of panic.