EDI - 810 interface

I have certain invoices which are eligible for EDI 810 outbound program, but in the header 0010 record in the edi outbound file I'm getting a value - T(which stands for test invoice) which causes our mailing program to reject this invoice.

My table definition(set up in ece_interface_tables and ece_interface_columns) says this column should be derived from ece_tp_details.test_flag which is currently set to 'P', but not sure why this is still comingup as T.

Is here a way to find out why this is coming up different than the value which is set up.