Hello,
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 then. Maybe one of the additional plugins is a reason for problems.
If this situation is not caused by a plugin, provide temporary FTP access (contact your hosting provider and ask for FTP host, FTP username, and FTP password) and wp-admin access.
Regards