Hello,
Thanks for using our theme.
1) Do you use a child theme? Did you make changes in theme files? Check if this problem is not caused by custom changes.
2) Try to disable all the third-party plugins (including cache plugins), that do not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear cache of browser, and check how it works then.
Let us know results.
Regards