I've checked your website and I can see you are running a recent version of X theme with an older version of Cornerstone plugin:
- X theme version 6.2.1 (that's the latest version).
- Cornerstone plugin version 3.1.6 (this isn't the latest version, you should have version 3.2.1)
You can follow this guide to update the theme or the plugin to the latest stable version:
Also, I can see you have these errors in the browser console:
You might need to reach out to your hosting provider about these errors, as they seem to be related to the server configuration.