Hello, Alex,
Thank you for your response.
1/ In order to troubleshoot the issue with you are experiencing, we suggest that you first try disabling all third-party plugins (including cache plugins) that are not bundled with XStore. You can refer to the following link for a list of included plugins: https://www.8theme.com/documentation/xstore/plugins/included-plugins/ . Additionally, please clear the cache of your browser and check again. It is possible that one of the additional plugins is causing the problem.
2/ Please check how it works when the default WooCommerce theme – Storefront is activated on your site.
Let us know the result.
3/ Do you see any errors in the browser console while getting the loader on checkout? Open it by right click > Inspect > https://prnt.sc/hTn3I8zssqbP Provide us with a screenshot of the results.
Kind Regards,
8theme team