My Imported Standard PO won't undergo approval.

My Imported Standard PO won't undergo approval,

i have to run Workflow Background Process just to trigger it to send to the Approver. Any Idea Why?

Here's the Sequence of what i did:

1.) I imported Purchase Orders using PDOI and somehow, it did not undergo approval. No data in PO_ACTION_HISTORY. AUTHORIZATION_STATUS = 'IN PROCESS' 
2.) I ran Workflow Background Process POAPPRV to force it to undergo approval. 
3.) This populated the PO_ACTION_HISTORY and the Approval Notification was sent to the first approver. 
4.) I rejected the PO using the Approver's Account so I can cancel the Purchase Order. 
5.) I tried to cancel the PO using PO Summary > Controls. however, it only displayed "Place on Hold" as the available Option.