change a supplier site email using FBDI

Summary:

Update the Supplier Site Email value using FBDI

Content (please ensure you mask any confidential information):
For targeted supplier site records, I am attempting to replace an existing communication emails, with a new email value using the Supplier Sites FBDI template. The template supports either Create or Update for record. When I select Update and enter the new email address in the Email column, the process runs, but adds the email to the suppler site. It does not REPLACE the existing email address.

How can I remove the current email and add a new value?

Additional details are when the process is run UPDATE, it add the new email address, but doe snot replace the existing email. I want the old email to be removed as a part of the update.