This happen because each price for products is rounded before send it to Paypal but the $products_amount used to find delta and discount is computed from addition of products prices not rounded.
So in some case the $products_amount is not equal to real addition of products this cause a false delta and add a fake product "discount" to compense where is not needed. And the total of products is not equal to order amount.
This happen because each price for products is rounded before send it to Paypal but the $products_amount used to find delta and discount is computed from addition of products prices not rounded. So in some case the $products_amount is not equal to real addition of products this cause a false delta and add a fake product "discount" to compense where is not needed. And the total of products is not equal to order amount.