While I don't have YouTube TV, I have the same issue with both Netflix and Amazon Prime TV. The bottom tier subscription to both no longer works when I hook up to the TV, and conversation with tech support revealed that the "solution" was to subscribe to a premium service with one (don't remember which now) and cannot be done with the other. And yes, it definitely does suck, but there it is. We have been able to watch on the slightly bigger screen of an iPad, but neither the iPhone nor the iPad can display on the TV. And I refuse to encourage this crap by subscribing to the premium service for the sole support of a TV.
