Accounts Payable and Payroll use the Last AP Check and Last PR Check on the Cash Management bank account to determine the next check number. When you print checks, the check number is one digit higher than the number in the Last AP Check or Last PR Check section.
If these boxes contain incorrect information, you can receive an error message, or incorrect check numbers will prefill when you print the checks.
If Payroll and Accounts Payable use the same Cash Management bank account, the Last AP Check can update incorrectly. This occurs when you void and reissue a Payroll check with the same check number.
If you altered the sequence in AP, it was likely due to the Manual check updates Last Check number in AP settings. See information about preventing manual checks from changing the sequence.
How do I void and reuse an Accounts Payable check number for error correction?
How do I reassign check numbers from an Accounts Payable check run?