Thank you. We have already compared the differences. Most of the plugin is technically irrelevant as were just using the PlayGamesSdk and GamesSignInClient in the GameActivity. We do modify the plugin a bit to call c++ after we retrieve the auth code and then fire the login delegates in Identity to bind our game code too.
It seems the issue is mostly on the PlayGamesSdk side not firing the addOnCompleteListener anymore. Although I am not sure why or if the plugin someone affects those dependencies.