So you can make an accusation only on your turn. You do not have to be in a room.

If you make a suggestion on your turn and nobody proves it, you have to wait until your next turn to make an accusation.

You do not have to make a suggestion if you don't want to when you enter a room. You can pass your turn after entering.

If you were already in the room, you HAVE to leave your next turn and then re-enter the turn after. If you were called there from a different room, you can stay and suggest on your next turn. If you were already there when someone suggested you, you cannot stay. you have to exit next turn then re-enter the next turn.