Delivery doesn't pick from Q-Stock as intended for NB2 Return Purchase Orders (S/4HANA OnPrem)

[t_jungesblut75]

We are facing an issue in the following process:

We receive goods from a supplier, and the stock is initially posted to quality inspection stock (Q-stock). Since the goods are defective, we want to return them to the supplier. For this, we create an NB2 return purchase order.
In the PO item, the stock type is manually changed to stock type X. By default, it is set to “Unrestricted-Use Stock”. Oddly, this manual change is not saved immediately. Only after reopening and editing the NB2 PO again and re-selecting stock type X does the setting remain in the document.

After that, we create outbound deliveries for the NB2 PO in order to return the goods to the supplier. However, in the outbound delivery, the system looks at unrestricted-use stock (where the quantity is 0), instead of checking the Q-stock (where the quantity is 20) – even though the delivery type is actually configured to look at Q-stock by default.

Has anyone experienced a similar issue?
Is there an explanation for why the delivery is looking at unrestricted-use stock?
Is there a way to ensure the outbound delivery picks from Q-stock as expected?
The only related SAP Note I found is 3528419, but as far as I can tell, the stock type can indeed be changed in the NB2 PO.

Thanks in advance for any ideas or insights!

[t_jungesblut75 · Accepted solution]

For users having a similar problem:

Note 3528419 mentions in its resolution, that "Changing the Stock Type to 'X - Quality inspection' should NOT be possible. System automatically reverts stock type to 'Unrestricted use'".

What seems to be confusing at first is that through some repeated clicking after saving the PO it is in fact possible to enter stock type X into the PO. 

The confusing part is, that the delivery doesn't seem to pick the right stock. But that is due to the ATP-check. The delivery does however book from the right stock after goods issue. To reach the desired result I simply had to disable the ATP-check for the relevant position type.

[Lakshmipathi]

In the SAP note you mentioned, it is explained to implement 3 other SAP notes in case you want to post from Quality stock.

[t_jungesblut75]

Unfortunately that didn't solve the issue. Is it perhaps not intended by SAP to create deliveries for return purchase orders using Q-stock?