Auto authentication firebase is not working via app.component.ts

When i put an authStateChange and try to set root page accordingly to the user are or arent logged in, the page isnt load instantly, it appear a blank page. But when i resize the browser window the page appears.

I also tried changeDetectorRef, but it causes some bugs in my login form.

This is my app.component code

export class MyApp {
  rootPage: any;
  constructor(platform: Platform,
    statusBar: StatusBar,
    splashScreen: SplashScreen,
    ionicStorage: Storage,
    autenticacao: AutenticacaoProvider,
    firebase: AngularFireAuth,
    private ref: ChangeDetectorRef) {


    platform.ready().then(() => {

      statusBar.styleDefault();
      splashScreen.hide();

      ionicStorage.get('OnboardPage').then((OnboardPage) => {
        if (OnboardPage || OnboardPage != null || OnboardPage != undefined) {

          let unsubscribe = firebase.auth.onAuthStateChanged((user) => {
            if (!user) {
              console.log(user);
              this.rootPage = 'LoginPage';
              unsubscribe()
            } else {
              console.log('logged', user)
              this.rootPage = 'TabsPage';
              unsubscribe()
            }
          });

        }
        else {
          this.rootPage = 'OnboardPage';
        }
      })

    });
  }
}

after resizing the window

Can someone help me please ? =/

See: Ionic phone authentication with firebase

Ionic 3 and Angularfire2 Auth sample code: https://github.com/appseed-io/ionic3-firebase-auth

For example: