Hi,
I see that you have several variants for the same values in your variants listing.
That should normally not be possible. It must come from a wrongly written CSV import.
Maybe it is linked to that ?
Try with a clean product where you don't have that.
Otherwise, try after changing the code:
$row->product_quantity_layout = $cart->products[$row->cart_product_parent_id]->product_quantity_layout;
$row->product_min_per_order = $cart->products[$row->cart_product_parent_id]->product_min_per_order;
$row->product_max_per_order = $cart->products[$row->cart_product_parent_id]->product_max_per_order;
to:
if(empty($row->product_quantity_layout))
$row->product_quantity_layout = $cart->products[$row->cart_product_parent_id]->product_quantity_layout;
if(empty($row->product_min_per_order))
$row->product_min_per_order = $cart->products[$row->cart_product_parent_id]->product_min_per_order;
if(empty($row->product_max_per_order))
$row->product_max_per_order = $cart->products[$row->cart_product_parent_id]->product_max_per_order;
in the file administrator/components/com_hikashop/classes/cart.php