I turned everything off for 2+ minutes, then started the modem, waited for it to finish, then started the router. Amber Internet light.
I got the old Asus up and running and copied the IP, mask, gateway, and DNS, and entered them all into the XR500 as a static address. Now the Internet light is white, but I cannot actually connect any of my devices (PC, phone, etc) to the Internet. They all say No Internet Connection.