Why Invoices from Auto Invoice program is Incomplete for 1BU while other BUs are in completed status

We have run the AutoInvoice program to import invoices from Subscription Management. All the invoices are imported to AR completing the transaction for all BUs, except one BU where invoices are in Incomplete status. We have checked the configurations in AR for all BUs and all looks similar. Why the Invoices are in Incomplete for one specific BU. Do we have any option to Auto complete all the Invoices in AR at once and not selecting manually each transaction to complete.