title: Angular 9: forkJoin subscribe not working
body: <p>I'm trying to load page data on a top level component in Angular 9 using observables (rxjs 6.5.1). When I subscribe to each of these services individually, I can see the data coming back just fine:</p>
  <pre><code>ngOnInit(): void {
    const technicianSubscription = this.techniciansClientService.getByTechnicianId(this.technicianId).subscribe(technician =&gt; console.log(technician));
    const technicianReviewsSubscription = this.technicianReviewsClientService.getByTechnicianId(this.technicianId).subscribe(technicianReviews =&gt; console.log(technicianReviews));
  }
  </code></pre>
  <p>When I try to use forkJoin, the data from the subscribe method is never returned:</p>
  <pre><code>ngOnInit(): void {
    this.pageDataSubscription = forkJoin({
      technician: this.techniciansClientService.getByTechnicianId(this.technicianId),
      technicianReviews: this.technicianReviewsClientService.getByTechnicianId(this.technicianId),
    }).subscribe(
      // data is never logged here
      data =&gt; console.log(data)
    );
  }
  </code></pre>
  <p>I've tried passing forkJoin an array of service calls and I've tried using zip as well, to no avail. What's happening here?</p>