Good evening Jamie and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
I would love to help you with this topic.
Yes, you are correct. This was a known bug a while back.
It has since been solved.
My best recommendation would be to attempt at least an upgrade to the following version of Event Tickets Plus (making sure that your versions of Event Tickets and the Events Calendar “match” as closely as possible.
But, after a good backup, I would totally recommend the latest version Event Tickets Plus which is better than ever.
In case you need to downgrade at any point during that process, here is a good link : https://theeventscalendar.com/knowledgebase/downgrading-plugin-past-version/
Let me know how that goes.
Best regards,
Geoff B.