If you cannot stream to a TV that you have synced to your phone:
Check the device’s state
If the TV appears as active but does not stream, try refreshing the devices page on your mobile app to see the current states. The TV needs to be Active in order to stream.
Make sure you are logged into the TV app
Logging out of the TV app will automatically unsync your phone from the TV. If this is the case, delete that TV from your devices. Then, log into your TV and sync both devices again.