displayName & ngIf not working properly

Angular
21

That looks like your UserService is not annotated to return the correct type of object. You can either change the return from that method or update UserService

22

I was able to find a solution here

so any one might face the same issue may change the code as follows:

get appUser$(): Observable<AppUser> {
    return this.user$
      .pipe(switchMap( (user: firebase.User) => this.userService.get(user.uid).valueChanges()));
    
  }