3819054 - Why does my invoice show both exception codes "COW" and "APPRVTO" at the same time?

My invoice was sent back to the employee during the Cost Object Approver approval step, and two exception messages were generated:
Code: COW, Level: 2147483647; The appropriate authority (limit or level) could not be reached for the following cost object(s)
Code: APPRVTO, Level: 2147483647; This invoice has been pending approval longer than allowed by policy.

And in the workflow, the Approval Time Expired Action is not set to Send Back to the Employee. Why is this happening?

The situation where both "COW" and "APPRVTO" exception codes are generated simultaneously in an invoice. , KBA , CON-EXP-ADM-AUR , Audit Rules , Problem