Unable to Update Invoice Number in Lease Payment Items When Payables Integration Is Enabled

Summary:

We are implementing a custom Lease Accounting extension to support a business requirement where multiple lease contracts are grouped into a single Accounts Payable invoice. The AP invoice is created successfully using the standard Create Invoice REST API.

As part of the process, we need to update the generated Invoice Number and Invoice Line Number back to the corresponding Lease Payment Items using the following REST API:

PATCH /fscmRestApi/resources/11.13.18.05/leaseAccountingPaymentItems/{paymentItemId}

However, when the Payables Integration option is enabled for the Business Unit, the PATCH operation fails with the following error:

"You can't update the payables invoice number and the invoice line number for the payment number 14005 in a business unit with Payables integration. (FUN-721106)."