That’s weird, I can’t seem to duplicate the issue on my end. Are you using any plugins that may affect the menu in any way….if so, can you try deactivating them to see if that fixes the issue?
I looked at your code and it looks like the “.genesis-nav-menu” class isn’t showing up in the “ul” code, and a couple other things about the menu look different as well. If the issue isn’t a plugin, can you explain exactly how you have your menu setup?