FCM token not created on user signup

Hi,

I’m building a mobile application with FlutterFlow connected to Firebase (Auth, Firestore, Cloud Functions).

My app is working correctly for:

However, I’m having an issue with Push Notifications (FCM).

When a new user is created:

In Android Studio logs, I see errors related to:

This seems to block the automatic FlutterFlow logic that should save the FCM token on signup.

Enabled Push Notifications in FlutterFlow
Verified Firebase configuration (google-services.json, SHA-1 & SHA-256 are correctly added)
Verified that Firebase Auth and Firestore rules are correct
Checked that notification permission popup is shown and accepted
Tested with a release APK
Tested on Android emulator (I plan to test on a real device as well)

Regarding App Check:

App Check is enabled in Firebase with Play Integrity for Android
Firestore / Auth / Functions are currently in Surveillance mode, not enforced
Logs show errors like:
- Error getting App Check token
- using placeholder token
- Cloud call error! addFcmTokenCode: unauthenticated

My understanding is that:

My question:

Is it expected that the FCM token is not available at user creation time?
Should we manually handle token creation/update (Custom Action) instead of relying on FlutterFlow default behavior?
Is App Check compatible with FlutterFlow push notifications when testing outside Play Store distribution?