Hi,
Well, I have finally find some time to make the debug. I am alone today for the support (bank holiday) so there is a lot to do.
So ! Please edit the file "administrator/components/com_hikashop/classes/discount.php" and replace
if(!$product->cart_product_option_parent_id) {
foreach ($id as $productid) {
if(!$product->product_id == $productid[0]){
By:
if(!$product->cart_product_option_parent_id) {
foreach ($id as $productid) {
if($product->product_id !== $productid[0]){
And it will reset the discount system right, as before.
Regards,