Voucher build process not populating paygroup

Hi,

We are FSCM 9.2 PI 26. We have interface from 3rd part vendor which loads the voucher staging tables. We then use delivered voucher build process to create vouchers. We anticipate that the voucher build process will populate the pay group (PYMNT_GROUP_CD) on the voucher payment reference table based on the supplier pay group default value setup on the vendor pay setup table. However voucher build process not populating the paygroup. Not sure if any one else encountered such issue or any possible solution. This was working fine when were 9.1, but any help / insight about this issue/solution is