How to insert one more click event inside ngbPanelTitle on ngbAccordion

I have added one more click event inside ngbPanelTitle. The click event is triggered on chrome browser (i can see console logs) but not on Mozilla firefox and IE 11/Egde.

You can see the below code in accordion-basic.html and accordion-basic.ts

<ngb-accordion #acc="ngbAccordion" activeIds="ngb-panel-0">
  <ngb-panel>
    <ng-template ngbPanelTitle>
      <span>&#9733; <b>Fancy</b> title &#9733;</span>
      <span (click)="headerClick()">inside title</span>
    </ng-template>
    <ng-template ngbPanelContent>content here</ng-template>
  </ngb-panel>
</ngb-accordion>

Edit: When I run the project, as a output I can see in browser this tag (<ng-template ngbPanelTitle></ng-template>) becomes button tag inside h5 tag. so im unable to trigger click event (on firefox) which comes inside button tag.

Demo - https://stackblitz.com/edit/angular-swevh2

My project runs with Angular above 6.0.7 and ngBootstrap 3.3.1