Hi Nat,
Thanks for reaching out! I’d be happy to help you with this, but first will you please post this question in our Events Calendar PRO forum? We use the Pre-Sales forum to answer questions about the features of our premium plugins for those interested in purchasing them.
If you have not purchased one of our premium plugins, you can post in our community forum on wordpress.org, which we review weekly to check for bug reports. If you need more in-depth support, you will need to purchase a license.
Our knowledgebase is a great place to start looking for answers. You can also search our premium forums to see if another user has posted about a similar issue. Since this happened after changing your theme, the best place to start is testing for a conflict.
Finally, I would like to note that while we do offer free versions of Events Calendar Pro and Event Tickets Plus to approved nonprofit organizations, access to post in our premium support forums does require a paid license.
I hope that helps!
Thanks,
Jennifer