Hello,
Took a look and seems to be working as it always has. Here is a screen shot of the cart with a $10 discount where the tax is 7%.
Product price - discount : 20 - 10 = 10
Tax 10 * 0.07 = 0.70
Total 10 + 0.70 = 10.70
As for the display you are using the calculation operation "Price modifier before tax per bill" or DBTaxBill. AwoCoupon does not modifier this DBTaxBill or DATaxbill. It only modifiers the tax, TaxBill. Even looking at the screen shot, you will see the $1.40 does not show under the tax column.
As a test, I changed it to TaxBill in the image below. As you can see, the tax shows under the tax column, and AwoCoupon makes the modification to make sure the tax displays correctly.
