I just noticed that the drop down menus don’t work on my iPad when I use Safari. They do work on Firefox for iPad. Im pretty sure they did work at one point, but can’t say for sure. I’m using the latest version of WordPress and Clean Retina (free), and the latest version of iOS on an iPad Air 2.
Can you please try adding # in the link field in your custom menu Non-Fiction? It may be not working because there is no href value in your anchor tag.