I've updated to tvOS 16 on both AppleTVs, as well as iOS 16 on my iPhone. I then updated to the latest pre-release of Channels DVR, and the latest TestFlight of Channels client on all three devices. I then followed the video example above, renaming the clients to "TV in Living Room," "TV in Bedroom," and "Channels on iPhone."
However when I use the Channels client app to play a show, the popup still offers "AppleTV," "AppleTV (2)," and "iPhone." Also when I go to Settings → Support → Device Display Name, on each client, I see these are still the names being listed, not the renamed titles that I'd entered in the webUI. So the changes aren't being recognized. I restarted the devices and tried again, no change. What else should I be trying?