Approved Enter Requisition Line did not auto create PO

Hello,

I created a Req using Enter Requisition Line using items from Item Master.  Once Req was approved, it did not auto create PO as expected.  The negotiated flag was selected.  A separate Requisition using SmartForm was created and approved, and it did autocreate a PO.  Why did my Req from Enter Requisition Line not issue an auto create PO?  Thank you.