Try to use the WiFi to Sign In to the game.Turn OFF any Network Restriction that might be ON from Settings > Data Usage.Goto > Settings > Date & Time > Turn ON Automatic Time.Goto > Settings > Date & Time > Turn ON Automatic Date.The problem here is that the Google Server is not responding or rather the request is failing before it reaches the Google Server. The Player launches the game, Sign In process takes place with a pop-up showing that there is No Active Internet Connection even when there is one. The Player has the game, but has never created a Google Gamer ID (ie fresh Google Account). Player's device has Google Account with no Google Gamer ID, does not Sign In to the game when using Mobile Data.(But works with WiFi). The launch the game and try Sign In the Sign In will work perfectly.Goto > Settings > Apps > Select Google Play Service > Storage > Manage Space > Clear All Data.
The Player launches the game, waits for the game to Auto - Sign In the game fails to Sign In to the Google Account. Player's device has Google Account with required Google Gamer ID, but still the game does not Sign In.