[firebase_messaging]: After turning off the device and turn back on, onBackgroundMessage is not fired on iOS.

[ViniciusSossela]

Steps:
1 - Turn off the iPhone real device
2 - Turn on the iPhone device (DO NOT OPEN YOUR APP)
3 - Send a push notification
The DEVICE will receive the notification, but the APP will not.
onBackgroundMessage is not fired on iOS in this situation

(After turning back on the device and opening it at least once, it starts to fire the onBackgroundMessage handler).
In other words, -->EVERY TIME<-- the device is turned off and on, the APP must be opened at least once, to start to fire onBackgroundMessage.

Is this a normal situation?

@russellwheatley can you help me with this?

Code:

@pragma('vm:entry-point')
Future<void> backgroundHandler(remoteMessage) async {
//my stuffs never called after turn on
}

Future<Null> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  FirebaseMessaging.onBackgroundMessage(backgroundHandler);

.....

  runApp(MyApp());
}