Hey Shane,
Welcome back!
Since we don’t have much experience and won’t be able to provide high level support for WP All Import plugin, I would recommend you to migrate your events from one calendar to another using WordPress Export Tools.
The migration process is pretty simple: we have an article explaining how to move events, venues, and organizers from one site to another. You will find further information in the following link:
https://theeventscalendar.com/knowledgebase/using-wordpress-export-tools-to-migrate-events-content/
I hope this helps! If this migration method is not working as expected, please let me know and I’ll be happy to further investigate your case.
Best regards,
Patricia