Photon Disconnection Problem

Hello, I have a card game which is on markets. I m using Photon Network. This is a realtime multiplayer game which has 4 players in the game. The game is all managed by master player. If slave player disconnects, there is no problem just that player disconnect, but if master player disconnects, game stops. i add this scenario inside "OnPhotonPlayerDisconnected" function, but the problem is, sometimes (often) any player, master or slave disconnects with no reason while playing. I couldnt understand why this happens. Do you have an idea?
Thanks