The customs forms do not reflect the correct order total if discounts are applied.
If a customer buys something and uses a coupon, the FULL amount of the retail price is shown on the customs form. However, the invoice shows the discounted price correctly.
This is leading to customers having to pay extra customs fees.
The only work around I was given by support was to set the customs forms to be manual and complete it for every order.
For such an automated system, this is a terrible solution. It should read the order invoice correctly and show the discounted price that the customers paid.