The reason why we show an item in the order item list that doesn't appear in the FBA console is that we did receive it from Amazon. We have verified this by looking at the data returned to Finale Inventory from our API calls to FBA.
This appears to be a bug on the Amazon user interface that is not showing the zero qty items or their order data that is allowing the zero data to be committed to the order and it is filtered out by their UI. They may be hiding the zero records from their user interface.
The received item has QuantityOrdered: "0" and QuantityShipped: "0" ... We do not know why it doesn't show in the FBA console: They may be filtering out "empty" order items, or maybe it's a bug on their side where an empty item like this ended up in the committed order.
Amazon's MWS documentation doens't specify that if either of QuantityOrdered or QuantityShipped appear in the order, they must be >0 . On the other hand, QuantityOrdered is mandatory so it's a bit suspicious that we could receive it set to zero:
We have verified many incidents of this where the data we receive via the Amazon FBA API is returning the items on the order with zero qty.
Finale Inventory is representing the data as we received it from FBA.