Can't Remove Items From Cart

I have noticed that if a user adds a product is no longer available at Amazon and then tries to checkout, it fails and cannot be removed from the cart. Clicking the red-x to remove it only loops back to same cart contents, and trying to remove it by changing the quantity results in same loop back to unremovable items.

I’d rather skip the SP “checkout page” and transfer cart contents directly to Amazon in 1 click. Is that possible?