FIltering ngFor with ngIf

Until now I had this

 <ion-item-divider (click)="toggleDetails(dataAssigned$)">
          <h2>Tasks assigned</h2>
          <ion-icon color="primary" item-right [name]="dataAssigned$.icon">
        </ion-icon>
  </ion-item-divider>
  <ion-item >[details=Summary]This text will be hidden[/details]
          <div *ngFor="let task of tasksAssigned$ | async" >
            <div *ngIf="dataAssigned$.showDetails">{{task.subject}}</div>
          </div>
  </ion-item>

so when i click on the Divider i could see the task content in the item. The porblem there was that i always saw the ion-item(empty).

So i tried to change it too:

<ion-item *ngIf="dataAssigned$.showDetails">
          <div *ngFor="let task of tasksAssigned$ | async" >
            <div>{{task.subject}}</div>
          </div>
 </ion-item>

But now, when I press the divider, the item appears but without content. Somebody knows why?Preformatted text

See here.