If a transaction, payment, credit, etc. fails to transfer to QBO for any reason, the item is marked to be resent, and the system automatically attempts to resend the data the next time you perform a CE => QBO transfer, and so on, until the error is corrected and the item is processed in QBO.
A report is generated for each transfer you perform. Select History to view all data transfers between your website and QBO. You can search by date range on this page, and run a report by clicking the reports icon next to any CE => QBO transfer record. The report shows invoices, payments, etc. that were included in that transfer. If there were errors for any particular item, the QBO error information is shown below the item, together with information about what to look for to correct the error.
If you fix the error manually on the QBO side, contact Customer Success to have us stop the transaction from attempting to re-import it in the next transfer you perform.