This seems like a known issue but I actually didn't find a solution for this anywhere.

In commerce, if I apply a discount/pricing rule to a certain product, add it to cart, and go to checkout, table would say eg

Product - 120$ (discounted from original 200$)
Subtotal - 200$

The subtotal is taken from the original product price and doesn't include the applied discount. It would be a lesser problem if that was just display issue. But the tax is then actually calculated from the subtotal, making the order total wrong

Is there a solution for that?