Pick release for back orders

Hi all please help

We did the following customazation on back orders:

The client wants the system to reserve stock for back orders when the new stock is received

-When the new stock comes in, the system will reserve stock  for back orders first before the new orders can be allocated

-We accomplished that but now the reserved stock cannot be released to the warehouse to be picked

-When we run the pick release for these back orders, the system will back order again instead of releasing to the warehouse

Any help will be highly appriciated

Kind regards

Lesedi