Sorry that I have to revive this old thread, but currently I have exactly the same problem.
Some background information:
Most content on my site is reachable via menu. But one article not, because I do not want a menu entry. So I linked to the specific article within another article.
The article shows up in my sitemap, but with an URL like this:
/cms/component/content/article/2-contentpages/93-xyz
When clicking this link, I don't see my menu, because the link has to be called like this:
/cms/category1a/category1b/2-contentpages/93-xyz
So I thought it would be a good idea to create an invisible menu entry with an external link.
But this link does not appear in the XML sitemap. And now we are at the same problem as discussed in this thread.
What exactly means this?
QUOTE:
The menu items of type 'External URL' require the domain address in order to be correctly validated by JSitemap and included also in the XML sitemap.
Do I have to set an absolute or relative URL in the menu? I tried both, both did not work.