Content is not visible for sub-level pages in Quark Theme

I am new, trying to figure out how to use Grav and I am having issues with the top navigation menu.

If you look at the site you can see that with the Quark theme, menu part of modules work fine, but then when I enter content for the pages, no mater what I do the pages are blank. At first I thought it was how I was creating content - but that is not the case - everything is routable and visible - the page renders - the header is visible, just not the body content.