Ionic 4 Service variables do not change their values

interface Profile {
  id: string;
  email: string;
  ...
}

class ProfileService {
  activeUser$ = new BehaviorSubject<Profile | undefined>();

  updateActiveUser(profile: Profile): void {
    this.activeUser$.next(profile);
  }
  
  peekActiveUser(): Profile | undefined {
    return this.activeUser$.value;
  }

  watchActiveUser(): Observable<Profile | undefined> {
    return this.activeUser$;
  }
}