Good evening Amber and welcome to the Events Calendar Support forum!
Thank you for reaching out to us and for providing your system info.
We are sorry to hear about the stock issue on your ticket products.
I would love to help you with this topic.
I have a couple of questions to help pinpoint what is going on.
First, could you confirm if:
Could you also please go through our testing for conflicts procedure (preferably in a staging/dev environment or local install of your WordPress website) and let us know what you find out.
Basically the goal here is to revert back to a bare WordPress installation to see if the problem persists. It also allows us to pinpoint what the cause of the issue is.
Once you have temporarily reverted to a default WordPress theme (like twenty-fifteen) and deactivated all third party plugins, could you see if the issue persist ?
Let me know how that goes.
Best regards,
Geoff B.