@XboxP3 @YouTubeTV @YouTube really need to work on the Xbox One YouTube TV app. Can stream HDX Vudu and watch HD/4k Netflix, but 480p YouTube TV is my max if I don't want a lot of buffering. Might as well ignore the 720p setting. If I'm paying monthly I want my apps to work well.
Sorry for the trouble, you can try via http://youtube.com/tv in Chrome & make sure you have the latest app version & device firmware. If you continue to experience issues, reach out to our live support team: https://yt.be/help/1oSc . They can help you further with this issue.