An easy way to fix this is with the POST stored procedure associated with taSopHdrIvcInsert. This would be the taSopHdrIvcInsertPost.sql file. Remember that each eConnect function is executed by a stored procedure with the same name and that each of these stored procedures has a PRE and POST that is executed before and after, respectively.
The Pre and Post stored procedures have a section for custom business logic, which is where we want to put the code, as follows:
/* Create Custom Business Logic */
UPDATE SOP10200
SET PURCHSTAT = 2
WHERE SOPTYPE = @I_vSOPTYPE
AND SOPNUMBE = @I_vSOPNUMBE
AND DROPSHIP = 1
AND PURCHSTAT <> 2
/* End Create Custom Business Logic */
Remember to check before modifying any existing code within that section!