When closing and invoicing orders, some invoices do not show item descriptions or item id's. All orders are imported through the SO API and this issue does not happen with every order. Is this a Sage 500 bug or could there be something wrong with the order import?
When you imported the items through the API, what does the sales order look like in Sage 500? Is it missing the information you want on the invoices? Also, what version of Sage 500 are you using? How are you creating the invoices? Are you using the Sage 500 functionality to pick and ship, or are you using another method?