I have recently added another MU site (subfolder) and mapped it with the WordPress MU Domain Mapping plugin, so instead of mainsite.com/newsite/ it displays as newsite.com. newsite.com is using a child theme, if that makes a difference.
I am intending to use the XML and Google News Sitemap with the new site as well. However, so far it just returns a 404. It works perfectly fine on mainsite.com/sitemap.xml, but doing the same with newsite.com/sitemap.xml, it does not function. If that helps, so far there are only static pages on newsite, no posts.
I have not touched anything in the site that may impact the plugin, i.e. fiddled with the robots.txt or something like that :-)
I appreciate any help. Many thanks!!