[cloud_firestore]: The service is currently unavailable.

[rbargux]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

Other

Which platforms are affected?

iOS

Description

When trying to query Firestore data on some iOS devices, I'm encountering this error:

The service is currently unavailable. This is most likely a transient condition and may be corrected by retrying with a backoff.

The strange thing is that it's constant; even with a backoff function implemented, the error persists. Furthermore, it only happens when I use specific combinations in my query, which is even stranger since it's the same code. I mean, if I use collection('app_setup').doc('features') it works, but if I use collection('app_setup').doc('status') it doesn't work and throws the error above.

The functions I'm using for the query are:

Future<T?> retry<T>(
    Future<T?> Function() callback,
  {
    int maxRetries = 4,
    Duration timeout = const Duration(seconds: 5),
  }) async {
    int retryCount = 0;

    while (retryCount < maxRetries) {
      try {
        return await callback().timeout(timeout);
      } on FirebaseException catch (e) {
        if (e.code == 'unavailable') {
          retryCount++;
          int delay = 1 << retryCount;
          await Future<void>.delayed(Duration(seconds: delay));
        } else {
          rethrow;
        }
      } on TimeoutException {
        retryCount++;
      }
    }
    return null;
  }

Future<Map<String, dynamic>?> readFeatures() async {
  DocumentReference<Map<String, dynamic>>? docRef = database
      ?.collection('app_setup')
      .doc('features');
  DocumentSnapshot<Map<String, dynamic>>? doc = await docRef?.get();

  return doc?.data();
}

Future<Map<String, dynamic>?> readStatus() async {
  DocumentReference<Map<String, dynamic>>? docRef = database
      ?.collection('app_setup')
      .doc('status');
  DocumentSnapshot<Map<String, dynamic>>? doc = await docRef?.get();

  return doc?.data();
}

 👍  Map<String, dynamic>? response = await ref
            .read(appConstantsProvider.notifier)
            .retry(readFeatures);

👎  Map<String, dynamic>? response = await ref
            .read(appConstantsProvider.notifier)
            .retry(readStatus);

Some logs

👍

👎

Flutter doctor

[✓] Flutter (Channel stable, 3.35.6, on macOS 26.2 25C56 darwin-arm64, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 36.1.0)
[✓] Xcode - develop for iOS and macOS (Xcode 26.2)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2025.2)
[✓] VS Code (version 1.106.3)

firebase_core: "4.2.1"
cloud_firestore: "6.1.0"

Reproducing the issue

basic flutter create and GoogleService-Info.plist

Firebase Core version

4.2.1

Flutter Version

3.35.6

Relevant Log Output

Flutter dependencies

No response

Additional context and comments

No response

[SelaseKay]

Hi @rbargux, thanks for the report. This appears to be a network-related issue rather than something directly caused by flutterfire. Could you please take a look at this comment and see if it helps in your case?

[rbargux]

Thank you so much for the quick response. This was the first thing I thought was happening, but we tried switching between mobile data and Wi-Fi, then to other networks, and the problem persists.

It's very strange, as I also reported above. When I check a combination in the FireStore app_setup>features, it works correctly, but when I run app_setup>status, it returns this error. Another curious detail is that we have the same connection in the office, and this only happens to one person.

P.S.: They don't have iCloud+, low battery, or the low data mode option in the network settings.