Invoice not Created for approved expense report

  US expense report 60376265 was selected for audit without any audit reason. Normally the non-audit reports should have audit reason such as Amount Over Threshold, Audit List Member,Policy Violation,Old Expenses,etc. However, the audit reason is blank,.Please suggest if I can check something ?? 

Also the hold_lookup_code holds value "Approver/Submitter is same" and invoice is not being crreated for this report even after it is fully approved.

select * from apps.AP_EXPENSE_REPORT_HEADERS_ALL 

where hold_lookup_code='Approver/Submitter Same'

 order by creation_date desc

There is no reject code.Please let me know if this is reason for Invoice not being generated.