Why can a user that was removed from a room still have the ability to enter it?
With mashme, generally every administrative user has the ability to create both public and private rooms.
In public rooms, any user can enter either if he is or not part of the room's attendance list. If a user enters a public room not being part of the attendance list, the email address of the user will be added to the list automatically as a new member and, if an empty seat is detected, he will be provisionally seated there when the session is launched.
In private rooms, the access to the room is only available to the persons invited (added) to the attendance list. If a user was at some moment part of the room and it is removed from the attendance list, the user will no longer be able to join the room.
If at any point, a different behaviour from the one presented above is detected, a ticket should be created and escalated so that the backend team members can review the room and see what is the reason that generates the behaviour.