Hi
Please observe that, even when if have activated automatic goods receipt and backflush, the goods movements are not posted automatically when you are using a BAPI. You must fill the goods movement table.
In order to make it easier, you can call BAPI_PRODORDCONF_GET_HDR_PROP before. This BAPI provides you the proposed data that can be used as input to BAPI_PRODORDCONF_CREATE_HDR.
BR
Caetano