Hello @Petro,
Thanks for writing in!
Could you please update to the latest versions?
Our latest versions are:
- X theme 7.0.4
- Cornerstone 4.0.4
This latest release contains fixes for several issues so be sure to check out the changelog (http://theme.co/changelog/).
After doing the updates, always remember to clear all caches (if you are using WP Rocket, WP SuperCache or W3 Total Cache) when updating so that the code from the latest release is always in use. This will help you to avoid any potential errors.
And since you are using SiteGround, could you please clear your site cache or temporarily disable the supercacher in your hosting panel? The SuperCacher is developed by SiteGround exclusively for their customers. It increases the number of hits a site can handle and boosts the website loading speed. The SuperCacher includes 4 different caching options for maximum optimization of your websites. You can access the tool by clicking on the SuperCacher icon in your cPanel.
For more information about this, please check it out here: https://www.siteground.com/tutorials/supercacher/supercacher_intro.htm
Please let us know how it goes.