Angular Material Tabs not working with wrapper component

material has changed the var names, so in the solution

tabs -> _allTabs

tabGroup -> _tabBodyWrapper

I think the issue you have is the same described in this github issue: https://github.com/primefaces/primeng/issues/1215

Basically the problem here is that ng-content does not provide @ContentChild when crossing component boundaries.

You can see that mat-tab uses @ContentChild: https://github.com/angular/components/blob/master/src/material/tabs/tab.ts#L56

So I think the only solution is to override it programmatically the way it is described in primeng issue.