title: Angular 7 scroll event does not fire
body: <p>For implementing a spy nav bar in my Angular app in a MatDialog component. 
  I implemented a directive to spy for the scroll event using</p>
  
  <pre><code>@HostListener('window:scroll', ['$event'])
  </code></pre>
  
  <p>I also tried <code>'scroll'</code> as event name. But the event does not seem to fire. I tried several approaches, e. g. by using the HostListener directly in the dialog component, by using the JavaScript <code>window.onscroll()</code> function and the rxjs <code>fromEvent()</code> function but without success.</p>
  
  <p>Trying other css events (e. g. <code>window:click</code>) work fine.
  I also tried it in a "normal" component that is not displayed as a dialog but the event is not fired there either.</p>
  
  <p>What could be the cause of this behaviour?</p>