@Shadow I clicked into helpful flags then clicked the question with this bug. It is a question with the title "Simple Interest" which belongs to MathsSE
So it means the question is deleted. Still a weird bug, but an edge case since you should not be able to see deleted questions in the app to begin with. It got deleted while you were viewing it.
@ArceusMaster0493 it'a automatic process, when enough comments are made between the same two users - a link is auto generated and clicking it creates such a room.