PO status "REQUIRES REAPPROVAL" but all shipment line is approved

Hi Team,

Few POs are in "REQUIRES REAPPROVAL"  status  but all of its shipment line is approved .

In po_headers_all tables , approved_flag is R for "REQUIRES REAPPROVAL" POs. But in po_line_locations_all table approved_flag is Y .

Is it possible approved_flag =Y  at po_line_locations_all  if POs are in "REQUIRES REAPPROVAL".

What is the significant for approved_flag in po_line_locations_all table ?