@kmessinger
I don’t think this is a Theme problem! The same thing is happening to ME also (started several hours ago). My Home page stopped loading, in the Root directory. If I type in my https://www.domain name only, I get my site, but it gives me a WP page that says “Not Found for the request archive”. Then I can press the Home button on the Menu and my Home Page loads properly!
If I type in https://www.domain name/home, then the site loads properly.
I too have my own custom menu, with the Primary Navigation SET to “Menu”, which is the title of my custom menu.
I am using the Twenty Eleven theme on my site, haven’t changed any plug-ins, etc and now this problem pops up?
Anybody that can help?