We'd like to understand this better. What happens when you try to stream YouTube TV? Have you tried any troubleshooting steps like uninstalling the app, restarting the device and reinstalling it? In most cases that does the trick. Keep us posted.
Sorry for the trouble. Next time this happens, please get in touch with our live support team who can look into this for you. Contact them here: https://yt.be/help/S7Hu