AirPlay (audio) to Silver Apple TV no longer workin

I was happily using my first gen Apple TV as some AirPlay speakers for a long time, but it seems that this capability (supplied by the Remote HD plugin) no longer works from my iOS (all upgraded to 9) devices. I can send audio from iTunes (latest version on the Mac), but iOS doesn’t work even though the Apple TV shows up in the list of destinations.

Any ideas? Are we blaming iOS 9?