**Issue description** Not able to delete the latest discount in the product's discounts list **How to reproduce** Steps to reproduce the behavior: 1. Select a product 2. Click on the Discounts tab 3. Add at least two discounts 4. Click on "Update" 5. Delete all of them 6. Click on "Update" 7. "Success" message appear 7. FIRST ISSUE : none of them is deleted 8. Delete them one by one (delete --> click on update) 9. SECOND ISSUE : They are deleted except the last one, when I click on "update" after deleting it, it appear again. **Expected behavior** When I click on update after removing one or multiple discounts, they must be removed. **Screenshots** 