When scanning from the up front scanner, if the doc does not have a barcode on it, you will need to scan the original from the first page. If you don't have that you will need someone like Julie print a new first page of the sales order.
Without the barcode, the scanner looks in an exact location that is setup with the original location. If you have a copy, the data might not be in the same location. The scanner tries to read the first page to get the data to upload in the database. If it can't get the data, it won't show up in the app.