We have identified and resolved the issue causing the 'Access blocked (Error 403: access_denied)' message for some testers.
1. Cause
The login failure occurred because the "Alpha" release track was not properly linked to the Play Games Services (PGS) tester settings, preventing the system from verifying tester permissions.
2. Resolution
The current Alpha release track has now been successfully added to the Play Games Services tester configuration.
3. Action Required
It may take some time for Google’s servers to sync this update.
If you still encounter the error, please force-close the app and try logging in again after a few minutes.
We apologize for the inconvenience and appreciate your patience as we improve the game. Thank you for your support!