Ring Doorbell Doesn't Connect

I've had a Ring Doorbell in a home we moved to two years ago. It's always worked fine (well, after I figured out how to activate it.) Anyway, now I can't connect to the video feed via iPhone. The bell still chimes and I get the notification but 'can't connect'. So I logged into Ring.Com, I can see the video feed from the website. Hmmm. I deleted the Ring app off my iPhone and re-installed it. But now if I tap Sign In, I get a blank page saying '406 Not Acceptable.' And, it's painful having to post a forum post about a doorbell.