Hello, @ForjarEmpresa,
Thanks for the login details I have checked your issue and found that you have not installed any multivendor plugin on your site, the page you are trying to edit “List vendor” is a page of vendors and the content on this page will be coming from the vendor plugin via a shortcode that’s why by default in the demo the shortcode is added in this page. When you install the plugin “WCMP check the image: https://postimg.cc/sBd0gzDQ” from the XSTORE >> plugin installer then check the page again after clearing the browser cache you will see the content.
Here is an article on it from our theme: https://xstore.helpscoutdocs.com/article/144-wcmp-with-xstore-theme
Regards 8Themes Team.