In the shopping_cart page, I did some testing and put items in and added quantities to have more than 1 QTY for each items. The unit, total and Sub-total price shows up and are all correct. But when I proceed to the checkout_payment page (Step 2 of 3 - Payment Information) where it shows the Billing Address, Payment Method, and "Your Total". Inside the "Your Total" section where it shows the Sub-total and total price. The value is incorrect. It shows the unit price from the previous shopping_cart page instead and not the supposedly Sub-total amount after the calculation. I'm suspecting the variable that is passing inside the php file isn't the correct one (using unit variable rather than the sub-total variable) I try looking into the checkout_payment.php file but didn't find anything there I need to change. Which file would it be to fix this little bug? Or is it in the Zen Cart Admin that I can fix this? Thanks in advance.

Here's the website https://www.alilang.com/
The bug can be replicated once you register and attempt to put more than 1 QTY in your checkout cart and proceed to checkout.