Angular 13: Material Tabs with bodyClass not working

Question

I set according the Angular Doc the bodyClass in the following example:

 <mat-tab-group animationDuration="0ms" [selectedIndex]="selectedIndex">

    <mat-tab label="Documents">
      <ng-template matTabContent>
                  <app-container1></app-container1>
      </ng-template>
    </mat-tab>
    <mat-tab label="Documents2"  [bodyClass]="'tab-item-meta'">
              <app-ref-main1></app-ref-main1>
    </mat-tab>
  </mat-tab-group>

and have in the corresponding *.scss file:

.tab-item-meta {
    height: 70vh;
}

When I open the Developer Console (either in FF or Chromium) I see that the class tab-item-meta is applied. But there the values of the scss file are not applied. When I try to add a code like

<div class="tab-item-meta">test</div>

then I see i.e. the class is applied. It seems like this extra attribute _ngcontent-mgf-c556 is missing for the mat-tab-body.

==> How to use the bodyClass properly?