When reporting achievements and leader boards I got an error 401, login required. I have a game in Google Play which use Google Play Games Services. When I go to Game services tab and choose my game I go to "Linked apps" section, select my game. At the bottom there is a OAuth2 Client ID for example
123456789012-randomlettersandnumbers.apps.googleusercontent.com
and than in console.developers.google.com under Credinentials tab above Client ID is missing. I have other one for example:
123456789012-reallydifferentrandomstring.apps.googleusercontent.com
Is it possible to restore first ClientID? Because I think this is a cause of 401 error.
OK I figured it out. To restore/use valid Client ID I need to link game again in Game Services. But there is one thing to fix on Firebase. In firebase console I have to download google-services.json (and add to game) again because Client ID change here as well.