I was having fun testing out duo on my Android TV. I went to launch it today and couldn't find it (normally it would be under all apps). I thought my kids must have uninstalled it. Went to reinstall it and it is definitely still installed. I just have no way of launching it now. Clever google!
Go to settings -> apps and try to find it there, uninstall it and reinstall it from the Play Store, there is an update rolling out today.