billing HU cost

Hi all

I have a strange behaviour:

if a delivery position TAN has header price condition ZTRA for freight transport, the condition goes in billing document

If the same item is packed into a HU, and the HU item is in delivery and billing, the same condition will not go in billing document

why???

I cannot understand why and what I have to check

is not a problem of copy control

waht is wrong?

regards