I just started to encounter this problem a couple of days ago on my Roku Streambar. I was having issues with Apple shows freezing up constantly. (Note: I have no issues with other channels.) So, I removed and reloaded the Apple TV channel thinking that might help - big mistake. Now I get the same sign in screen with no option to use my mobile device/QR code, and signing in with the remote gets the "Verification Failed" message (Error Code: N/63D93E47). None of the workarounds recommended in this thread have worked, so the only thing that I can do until this app issue is fixed is to stream Apple programs on my Apple devices and use Roku's Airplay feature to show them on my TV. Has anyone received an update from Roku Support on their issue tickets?