Missing invoice/supplier
This is often manifested with a mismatch of supplier details showing on an invoice and/or it missing from manual reconciliation.
Check Focus>Accounts Payable>Supplier – change the view to All and page down for any suppliers with a tick in the on hold column. Clues maybe a similar supplier name or if the school knows the supplier has changed its name.
It may be the supplier with the attached invoice has been put on hold, taking it off hold will show the invoice.
KB18757