Hello! 

Sorry for my English

1. There is an account with a linked Google play

2. Send GooglePlayConnectRequest with new account Google Play

3. Response - error " ACCOUNT_ALREADY_LINKED", (switchIfPossible - false)

4. Result - GS.GSPlatform.UserId  == "empty"

Also, if there are two accounts with a linked Google Play (switchIfPossible - true) , when switching between them sometimes -result  GS.GSPlatform.UserId  == "empty", also at this time...

GS.GameSparksAuthenticated += delegate(string _userId) 

{

  playerId = _userId;

// userId == empty

  };

But in the Cloud Code you can get playerId