How to change the Warehouse Process Type for EWM Inbound Delivery

Dear Experts,

I try to perform following test:

I create an inbound delivery in ERP system with MB1C:

After this I perform the packaging by using VL32N:

At the end I distribute this delivery to my EWM System by using of VL06I:

So when I switch to EWM system, I can find my inbound delivery:

As the next step I try to change the default Warehouse Process Type but for some reason even it an editor modus it is not possible:

Why is this change not possible? Do may be someone has any hits?

Thanks in advance

BR

Denis