Coupon code applied, listing fee becomes $0, but still require to make payment

If set the discount coupon to 100% off or the full price of the listing, the listing fee becomes $0, but the user still need to click on the pay now button and then redirect to Paypal for payment. Why customer still needs to pay the $0? It should be a free listing and user should add the listing without going to any payment.

It supposed to be like If the coupon discount is more than the listing fee, the listing automatic goes free and not sending to Paypal or other payment method for processing?

Also for the listing per package, after applying the discount coupon code, the window closed and user will have to click make payment button again to pay. It’s confusing. I think after the discount coupon code is applied, user should be able to make payment right there without having to click on the make payment button again.