As the title says. I have a Sonos 5.1 Surround setup with a Playbar, a Sub, and 2x Sonos Ones. If I remove the two Sonos Ones from the surround setup, and set them up in a Stereo Pair, they appear as AirPlay targets. If I then re-add them back to a Playbar/Sub/2xSonos One Surrounds configuration, they disappear from AirPlay and the Sonos App says "You don't have any AirPlay-compatible speakers."
This surely can't be intended. I went out and purchased 2x Sonos Ones to use as surrounds and replaced my 2x Sonos Play:1s because Sonos stated that grouping AirPlay compatible speakers with non-AirPlay speakers would make the whole group AirPlay capable.