Error: Billing Created with Net Value 0

Dear Expert,

I have created a new billing type, for order-related billing.

I have successfully created the sales order. The net value is not 0.

However, when i create the billing with reference to the sales order, the net value reflected in the billing is 0.

The price condition type values are copied accordingly from sales order (not 0).

I have checked the copy control from sales order to billing, the pricing type is "D" (copy pricing element unchanged).

Please assist.

HJMY