Good evening Charles and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
We are sorry to hear about the issue you are experiencing with the mobile version of your site.
I would love to help you with this topic.
What seems to be going on is that the responsive CSS rules are not kicking in on your installation.
The first thing I would recommend trying out is playing around with the first two settings found under Events -> Settings -> Display to see if that helps.
If not, I would recommend turning the caching off (WP Fastest Cache) to see if that changes anything.
Let me know how that goes.
Best regards,
Geoff B.