Third Party Photon player object create twice when join game

(Probably there is a thread about this but i am still doing it)
background :
I am creating a game where players can join a lobby scene before they actually load the game scene. if all players is ready then the game scene will be loaded. I do this by creating a class LobbyPlayer for each player using PhotonNetwork.Instantiate which stores a bool isReady. it got sync by OnPhotonSerializeView so eveyone know other people's isReady.

problem :

     A                    B

     create room          -

     create LobbyPlayerA  -

     -                    Join room

     create LobbyPlayerB  create LobbyPlayerB

     create LobbyPlayerB  -

I am calling PhotonNetwork.Instantiate on Start. I have no idea whats going on...
how do I suppose to keep track A on B's side and why LobbyPlayerB got Instantiate twice...
Does anyone know?

 

It got solve as soon as I post this... I found Start() called twice in B side and the reason is B has load lobby scene from custom room properties. then I load the scene again in OnJoinedRoom.