Setting a timeout in GKTurnBasedMatch doesn't work... GKTurnBasedParticipant.timeoutDate is always nil.

I have created a turn based game using GameKit. Everything is pretty much done, last thing left to do is the turn time out.

I am passing GKTurnTimeoutDefault into the timeout argument in:

func endTurn(withNextParticipants nextParticipants: [GKTurnBasedParticipant], turnTimeout timeout: TimeInterval, match matchData: Data)

However when I check the .timeoutDate property of the GKTurnBasedParticipant participants, the value is always nil.

What am I doing wrong? Am I checking the right property or is there another one instead that I don't know about? I have tried passing different values to the timeout parameter but the timeoutDate is always nil.

Has anyone successfully implemented a timeout using GKTurnBasedMatch ?