Release procedure for PO

Hi Experts

How to use release procedure for PO with cekko structure, components LIFNR - Vendor's account number. I have create other release procedure with GNETW - Total net order value and it works well. But this for LIFNR does not work at all. The idea is that all PO to selected vendors have to be accept. Is it any differences between LIFNR and GNETW components ? In PO header Vendor's account number has only 5 lenght and full name. In CEKKO this component have lenght 10. Maybe here is problem?

THX