Remove button did not work when user try to delete an in stock item when it was back ordered

Steps

1. Run https://www.novica.com/
2. Login
3. Search for item “302351”
4. Click on add to bag
5. When “Place Backorder ” button displayed , click on it
6. Go to the cart
7. Click on remove for the “in stock ” item
8. Now the remaining item on the cart become in stock
9. Try to remove it by clicking on remove button

Actual result

Remove button did not work when user try to delete an in stock item when it was backordered

Expected result

Remove button should be work when user try to delete an in stock item when it was backordered