Sitemap not found if the plugin is enable…

Hy guys. I notice that if i enable your plugin, a tool like varvy*com don’t find my sitemap.
If i disable the plugin, the tool find and say to me that my site has a sitemap.

Is there some problems or maybe i must set correctly something on the setting of itheme security?

Ah, i auto create my sitemap with the plugin Google XML Sitemaps

The page I need help with: [log in to see the link]