Connecting to vCenter just spins

I have 6.7u2 installed. I can connected to my vCenter host at its URL by hostname, and I can launch the HTML5 client and get connected to the login screen. Once I login, I just get a spinner and never connect. If I connect to the vCenter URL by IP address, I am able to connect all the way into the UI. Any ideas what's wrong? Since I can get to the login screen by hostname, it does not seem to be DNS related.