Good afternoon Frank and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
We are sorry to hear about the calendar not displaying on your website.
I would love to help you with this topic.
The very first thing I would recommend is trying out the different Events Template settings under Events -> Settings -> Display to see if that helps.
If it does not, could you please send me a copy of the latest version of your WordPress theme / child theme via a link to a .zip file link (stored Dropbox or Google Drive) so that I can run some tests on my end ? I recommend a private reply for that purpose.
Please ensure you are using the latest files as found on your actual website.
This way I will get access to any updates or customizations you might have made.
Hang in there!
Geoff B.