Backflush in OSP WIP job does not allow Negative balance

Hi,

When we make a WIP transaction in a Discrete job, the backflush allow negative balance in inventory.

However, if the WIP Trx belongs to a job that includes OSP (outside processing), negative balance of components is not allowed.

This means that, in case we don't have enough quantity of a component in the supply subinventory, the transaction will fail instead of get completed by creating negative on-hand quantity of components.

Why?  How can we modify the setup so that we can go in Negative balance of a component that is consumed in a WIP job upon the receipt of a PO?