In child component ngOnChanges() is called twice for each array element.
this is my category.html
<ng-template ngFor let-fourlet [ngForOf]="productFourlets()" let-i="index">
<div class="row" >
<pdp-product-list-item *ngFor="let product of fourlet"
[product]="product"
[category]="category"
class="col-xs-12 col-sm-3 col-md-3 col-lg-3 product-item">
</pdp-product-list-item>
</div>
</ng-template>
productFourlets() is function that returns array of arrays. Example here Angular 2 *ngFor - Conditional wrapper element. Like using bootstap row with three columns inside, then add a new row
So something is really off here in pdp-product-list-item component elements are received via @Input() and then half a second pause and the same elements arrive again.
This causes all kind of problems in child component
Anyone experienced this ?