angular api not executed

I have a component to display the details of ExerciseFramework object, so in the ngOnInit i call an api that returns the ExerciseFramework object to display it, and i have a form in this component to update a part of this object. I have the saveJoinability function that updates and call again the api that returns the ExerciseFramework object to refresh the data that will be displayed. But that api is not executed

  public exerciseFramework$: Observable<models.ExerciseFramework>;

  ngOnInit() {
    this.exerciseFramework$ = this.apiExerciseFramework.findExerciseFrameworkUsingGET({ externalId: this.externalId });
  }

  public saveJoinability(event: SendData): void {
    this.apiExerciseFramework.updateJoinabilityUsingPATCH({ updateJoinabilityRequest: this.args }).pipe(takeUntil(this.updateDestroyed$)).subscribe();
    this.exerciseFramework$ = this.apiExerciseFramework.findExerciseFrameworkUsingGET({ externalId: this.externalId }); // is not executed
  }

  <ng-container *ngIf="(exerciseFramework$ | async) as exerciseFramework">

  </ng-container>

Source: New feed
Source Url angular api not executed