We offer membership plan for 500 yen, and we also offer various coupons for our customers; one of them is a free product coupon where if a customer`s minimum order spent exceeds 2000 yen, we give them a free product.
The problem occurs when the two factors above are combined; if the customer becomes a member and uses this coupon, the total cost becomes only 500 yen and the rest of the item becomes 0 yen.Please see here for the print screen image of the cart:https://ibb.co/t4PDNR2
We tried to pinpoint the problem and found that if the minimum order spent is below 500 yen this problem does not occur. However, if it is 501 yen or above this problem occurs.
I am using version 3.2.9