Hello,
We’ve temporarily disabled Ajax pagination/filtering via Theme Options, the bug is disappeared now and your site works fast. Check video in the Private Content area.
1/ Please test it from your side, and let us know.
If the problem is solved for you too, it means something wrong with the Ajax functionality. We did not get reports from other customers about this problem, so it can be a conflict with a 3rd party plugin on your site, or something else.
2/ Try to disable all the third-party plugins, that do not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear cache of browser, enable Ajax pagination and Ajax Product Filters via Theme Options, and then check. Maybe one of the additional plugins is the reason for the problem. Let us know the result.
3/ Could you provide temporary FTP access? then I will ask our dev team to check the situation of your site more deeply.
Waiting for your reply to 3 questions.
Regards