Help & troubleshooting for channels on your Roku device, including adding/removing channels, logging in to, authenticating, or activating a channel, channel-specific playback issues, assistance contacting channel publishers to report issues, and adjusting channel-specific settings.
First, the contract dispute between Google and Roku only affects the YouTube TV app, not the YouTube TV service, nor YouTube (app or service). Let's rule that out.
There have been some issues with some users resulting from a problem on Google's end with YouTube service to Roku devices -- there are separate servers that Google uses for the major platforms; Roku devices get content from one bank of servers, Apple TV gets content from another bank of servers, and so on. Those issues were resolved, according to Google and Roku, and required a restarting of the device. I never experienced the issues on my Roku devices, so I didn't have to deal with that. Here is Roku's posting of the resolution: https://community.roku.com/t5/Channel-Issues-Questions/YouTube-not-working-Sept-2021/m-p/720490/high...
I'm going to suggest trying a factory reset on the impacted Roku Ultra (not Ultimate). Be sure that with power applied, you press and hold the Reset button for no less than 30 seconds. Unless the device has gone bad (that model Ultra was released in 2017 and should still perform well), the 30-second reset should clear everything out and allow you to set things up.
I will suggest that you log in to your Roku account on your computer before clicking the link in the email to set up the device. That would ensure nothing on your computer is impacting the setup.
DBDukes Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." Note: I am not a Roku employee.