This is a new thing, but it could be for any number of reasons. When I visited for MAP day there was a birds nest on of the 'leg' nearest the toilets, which could be preventing it from opening. Or it could be a technical issue, or a staffing issue or something completely different. Until TP decide to tell us, we won't know for sure. However, just looking at Twitter and they are saying its for maintenance.
Even the good can fall from grace