The Linked box means the lines exist on a Purchase Order in Dimensions. First check that the Purchase Request is not still Pending or Awaiting Approval — until the Purchase Request has been posted, it is correct for lines not to be linked. If the Purchase Request is fully posted, those unlinked lines do not currently exist in Dimensions. If all lines are unlinked, check that the Purchase Order still exists in Dimensions — if it has been deleted, you will need to raise a new Purchase Request and start again, as Support cannot recreate deleted transactions or force a link.
