Hello,
1, 2/ Please try to disable all the third-party plugins (including cache plugins), that does not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins , clear the cache of the browser, and check then. Maybe one of the additional plugins is the reason for the problems.
3/ Download the file from this page – https://dropmefiles.com.ua/en/8Ba4L2TX You can import it via Single Product Builder > Import/Export. Of course after solving the first 2 problems.
Regards