Estimated_delivery always NULL for orders

Is it possible to get an POs estimated delivery on an order via API? Currently estimated_delivery always shows null even when there is a eta on the PO. Is this a bug or am i missing something please?

Definitely not always null:

            [supplier_id] => 361817
            [destination_warehouse_id] => 99992
            [state] => active
            [created_by_id] => 364075
            [updated_by_id] => 364075
            [created_at] => 2026-04-29T17:51:00.000Z
            [updated_at] => 2026-05-14T04:11:09.401Z
            [expected_date] => 2026-06-18T23:00:00.000Z
            [estimated_delivery_days] => 50
            [currency_code] => GBP

Presumably it depends on the status of the PO.

But not set at product level - just get the PO