Destroy player from network after rejoining room

When I create or join a room, everything seems to be okay. But when I disconnect from photon and create or join another room, I have 2 players with mine photonview. The previous player with mine photonview does still exist. Anyone that could help me? It drives me crazy, I even don't know how to explain because of this headache. Please help me out

My code is quite simple.

In the NetworkManager, I use this part of script

// This buttonEvent is only for the masterclient
[PunRPC]
public void LoadGame ()
{
SceneManager.sceneLoaded += (scene, loadscene) =>
{
if (SceneManager.GetActiveScene().name == "GameRoom")
{
Spawn();
}
};
PhotonNetwork.LoadLevel("GameRoom");
}

void Spawn()
{
GameObject g = PhotonNetwork.Instantiate("Player", new Vector3(Random.Range(-2.7F, 1.1F), 0, Random.Range(-22F, -16.5F)), Quaternion.Euler(0, 90, 0), 0);
}


And ingame, I use this part

public void ReturnToMenu()
{
PhotonNetwork.autoCleanUpPlayerObjects = true;
PhotonNetwork.Disconnect();
Application.LoadLevel("MainMenu");
}