Epicor 905.700B, Copy a UD Text Field to another UD Text Field

In Epicor I'm trying to copy a UD field in the Order table to another UD field in the JobProd table. When I analyze the code in the Method Directive I don't get any errors, and it saves without any errors. The issue is that the UD field never gets updated.

Below is a copy of the ABL code. Can anyone tell me what I'm doing wrong?

/*
Purpose: copy OrderDtl Early Delivery Limit value to JobProd.shortchar04 for use with DD BPM.
Business Object: Job Prod.
Method: GetDetails.
Directive: Post-processing.
Additional Info: In-transaction data directive on JobProd is dependant on this BPM.
*/

FOR EACH JobProd FIELDS (shortchar04) WHERE JobProd.company = cur-comp AND JobProd.ordernum = OrderNum AND JobProd.OrderLine = OrderLine NO-LOCK.
FOR FIRST Orderdtl FIELDS (shortchar04) WHERE Orderdtl.company = JobProd.cur-comp AND Orderdtl.ordernum = JobProd.OrderNum AND Orderdtl.OrderLine = JobProd.OrderLine NO-LOCK.

IF avail JobProd THEN DO:
ASSIGN Orderdtl.shortchar04 = JobProd.ShortChar04.
END.
END.