Hi Alex,
I’m sorry that you’re running into this issue, but I’ll be happy to help you out.
The featured image should be displayed in a tooltip when you hover over an event in month view; you can see how this looks by default hereon our demo site. I took a look at your site, and the tooltips are not appearing.
As a first step, can you try adjusting the “Default stylesheet used for events templates” and “Events template” settingsunder Events > Settings > Display. These affect how much events pages inherit their styling from the theme. Make sure to clear out your browser cache and any server/site caching you might be doing – you’ll also want to disable the month view cache by unchecking the Events > Settings > Enable the Month View Cache setting.
If that doesn’t make a difference, the next step would be to run through the instructions outlined hereto check for any conflicts that might be occurring with your theme or another plugin. Make sure to have WP_DEBUGenabled and copy/paste any errors that you see here.
Can you also share your full system infowith me?
Thanks,
Jennifer