The order number is likely already used in Sedona's integration tables. Could be from copying, the order already being linked to a job, or from deleting old orders in QW and QW reusing the numbers cleared. SedonaOffice can't see when something is deleted from QW, so if the order was linked to a job before and then deleted, it can cause the issue.
The solution is to renumber the orders you expect to see in QW.