The issue occurs because Google Play uses a different App Signing Key in production mode. To resolve this:

Check the App Signing Key in Google Play Console:

Go to Google Play Console → Setup → App Integrity. Copy the SHA-1 key under the App Signing Certificate section. Update the App Signing Key in Firebase:

Go to Firebase Console → Project Settings → Your Apps. Add the SHA-1 key from the Google Play Console under the SHA certificate fingerprints section. Save your changes, and your Google Sign-In should work correctly in production.

No additional configuration is required. Let me know if you need further clarification! 🚀