I've checked disconnecting and reconnecting signalling server via Multiplayer plugin but, as you said, this doesn't solves nothing.
Will try to check what's going on and if there's a workaround. If so I will post here.
I left the capx file to also download my STROKE MULTIPLAYER project in Scirra Arcade, the problem was caused because no one said that the PEER GROUPS HOST and remain connected even after finish the game and change layout,,, what caused the bugs when in the second match was reversed players.