Apple Support is repeatedly telling customers this is a Roku issue and not an Apple issue. Please reach out to your contacts within Apple and include the 20+ support posts then maybe they will better understand how this is on them to fix.
Opened a support ticket with Apple today and was working with a support engineer from the meda services group. It appears this issue is known to apple since the support tech I worked with has seen this before. Basically she had me enable Secret Screen 2 on the Roku (5 x Home, up, right down, left up) "Log Info" "Start Verbose Logging" start the Apple TV app and try to login. Go back to the home screen and give the "tracker id" to support (5 x home, 5 x back). Apple support is calling me back tomorrow to continue troubleshooting. Will keep you guys posted.
Issue occurs with Apple TV channel (version 13.0 - build 55)
Issue ID: K6-478-247
When attempting to log in to the Apple TV app, you do not get an option to log in via mobile - only to log in via remote. When you input your username and PW, you get the following message: "Verification Failed. There were errors signing you in. Wait a moment, then try again."