GetIt - Instance shows as registered but then it become unregistered

Question

So GetIt is acting a bit weird and I couldn't figure out why! After calling the setupLocator() in main function. I wanted to check if an instance if registered or not; but for some reason the isRegistered functions returns True in MyApp class but False in AuthenticationScreen!

  Future<void> setupLocator() async {
  // Use Cases
  sl.registerLazySingleton(() => LogoutCurrentUser(repository: sl()));
  sl.registerLazySingleton(() => LoginWithEmailAndPassword(repository: sl()));
  sl.registerLazySingleton(() => SignupWithEmailAndPassword(repository: sl()));

  // Repositories
  sl.registerLazySingleton<AuthenticationRepository>(
    () => AuthenticationRepositoryImpl(
      networkInfo: sl(),
      hiveDataSource: sl(),
      firebaseDataSource: sl(),
    ),
  );

  // Other services...
}

I'm calling the setup function in main:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Hive.initFlutter();
  Hive.registerAdapter(UserAdapter());

  // Here!
  await di.setupLocator();

  runApp(
    DevicePreview(
      enabled: false,
      builder: (_) => const MyApp(),
    ),
  );
}

But now something weird happens! I did a check if LoginWithEmailAndPassword() isRegistered in MyApp widget it returns True, but in another screen AuthenticationScreen it returns False!

This is MyApp Screen:

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final _navigatorKey = GlobalKey<NavigatorState>();

  NavigatorState get _navigator => _navigatorKey.currentState!;

  @override
  Widget build(BuildContext context) {
  // Returns True
  print(sl.isRegistered<LoginWithEmailAndPassword>());

    return BlocProvider(
      create: (context) => AuthenticationBloc(
        authenticationRepository: sl<AuthenticationRepository>(),
        logoutCurrentUser: sl<LogoutCurrentUser>(),
      ),
      child: MaterialApp(
        navigatorKey: _navigatorKey,
        useInheritedMediaQuery: true,
        locale: DevicePreview.locale(context),
        builder: (context, child) {
          return BlocListener<AuthenticationBloc, AuthenticationState>(
            listenWhen: (previous, current) =>
                previous.status != current.status,
            listener: (context, state) {
              switch (state.status) {
                case AuthenticationStatus.authenticated:
                  _navigator.pushNamedAndRemoveUntil(
                    HomeScreen.sRoute,
                    (route) => false,
                  );
                  break;
                case AuthenticationStatus.unauthenticated:
                  _navigator.pushNamedAndRemoveUntil(
                    AuthenticationScreen.sRoute,
                    (route) => false,
                  );
                  break;
                default:
                  _navigator.pushNamedAndRemoveUntil(
                    AuthenticationScreen.sRoute,
                    (route) => false,
                  );
              }
            },
            child: DevicePreview.appBuilder(context, child),
          );
        },
        title: 'App',
        onGenerateRoute: RouteGenerator.onGenerateRoute,
        initialRoute: '/',
      ),
    );
  }
}