Third-Party Apps Won't Authenticate
When attempting to authenticate to third-party TV apps on the Apple TV (I've now tried History, Lifetime and Hallmark), authentication won't work. For History Channel and Lifetime, I get prompted to go to a website and enter an authentication code. Much like a recent poster in this forum, I pick "DirectTV NOW", put in the code, hit the button and either A) get a blank box (if on my phone or iPad) or I get an error window (if on my desktop). For Hallmark, I get a slightly more useful error code, directly on the Apple TV ("Your TV provider (ATTOTT) is not currently available. If logged in through Single Sign-On, please disable it in app settings").
I've tried logging out of DirectTV NOW and then logging back in on my AppleTV, but it doesn't make a difference.