Fields are not edit when add the table collections to virtual company accounts

HI All,

I added ‘TaxwithholdTrans’ table to the virtual company accounts by using table collection and i post the invoice journal(IN Ap) and i do the payment journal to settlement(previous posting invoice journal). before doing settlment, in settlment for there is one tab is there ‘taxwithhold’, while creating new record here the withholdtrans table fields like withholdtax group and withholditemtax group fields are showing as disable. but we need to enable for this fields. but when doing without virtual company setup, this fields are enabled.(This is Thailand country region)

Could you please help me how to enabled those fields when setup the table collections using virtual company accounts.

thanks…