Having Unassigned Delivery from a delivery detail in Shipping Transactions form, no new delivery is

With reference to Note 306202.1. we have to unassign all unstaged delivery lines assigned to deliveries as a business process in order that the automated ship confirmation process will ship confirm all eligible lines in a delivery in status staged.

Attached is screenshot of order lines in shipping transactions form After I've done the 'Unassign from delivery', Go. Note No new delivery is being created for the line at 'released to warehouse' status. Is there a set up we are missing (shipping grants?) that would allow a new delivery number to be auto- assigned to this line at released to warehouse status. We shouldn't have to do 'autocreate new deliveries", as a manual process. This seems to be working in one instance but not another.