Nav back btn disappears

Hi, building my first ionic 2 app and loving it so far. Have run into a hurdle where trying to show and hide the navbar based on a *ngIf fullscreen variable. When the nav gets shown again, it has lost the back button, even though from debugging I can see the nav controls view stack is the same. See plunker here for example https://embed.plnkr.co/c0msjyOVvfWj4SwDICoI/

Wondering if there is another way I should be doing this or if this is a bug?
Thanks!

maybe instead of using *ngIf=“condition” you cold use [hidden]=“condition”, there a diference between than.

Thanks mate that did the trick!

Actually when testing further, it was not working once implemented into my events - probable bug?
Went with the ugly solution for the same problem posted here: Events, Show Hidden Elements