Good afternoon James and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
We are sorry to hear about the struggles you have been experiencing with the CSV imports.
I would love to help you with this topic.
As a first troubleshooting step, could you please provide us with your complete system information in a private reply using the instructions found in the following link?
https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Secondly, would you mind sharing the csv file you are working from ? (via a link to a .zip file on Google Drive or Dropbox)
Hang in there!
Geoff B.