Assign Flexi task - Assignee = "Created By", but not getting e-mail

I have 2 different lists with workflows.

List A has a workflow with an “Assign Flexi task” box.  The Assigneee (“Created By”) is e-mailed if their request was successfully completed.  It works fine, and sends an e-mail to “Created By”.

List B did not have this workflow, so I exported/imported from A to B, made sure all parameters were good and then published.

However, the e-mail does not go to “Created By”, it goes to the person who worked the case  - so either Assigned to or Last Modified by.

I’ve tried changing the e-mail Assignees in the Flexi task, verified that “Created By” is valid, but nothing works.

Anyone have any ideas how to make this work?