No products on packing slip / invoice

[Marcel Meijer]

Hello, I use Channable link. They transfer orders from an external site to my webshop. Now this is going well, however, I do not see any products on the invoice and packing slip. the total amount is. Had contact with Channable and they indicate that it must be an error of Prestashop. If I create an order myself and the orders that are placed in the web shop, he makes the packing slip and invoice properly. (article is then on the invoice and packing slip) orders that come in externally Anyone have an idea? Marcel