Hi Fred,
Please see the sample posting of supplier ID in the migration file and after migration of the supplier account ID and i found it same.
Please check if you are referring to the correct file
In each migration unit you might have filled with different supplier IDs, are you referring to the correct file which is set to Completed ? Please crosscheck and reply in case of any further issues.
Please mark the thread as answered/helpful if your query
Thanks
Lokesh Sharma