I have an AppleTV 4K connected to a soundbar in my living room and an AppleTV 4th gen connected to a TV in my guest room. With AirPlay 2 I can output music from Spotify to both, but the audio goes slowly out of sync. If I disable the guest room ATV and re-enable, the audio is in sync again, but by the second song it’s again hundreds of milliseconds off.
Both are connected with WiFi to the same access point, running the latest tvOS, no other AirPlay sinks in the networks.
Isn’t AirPlay 2 specifically supposed to enable this use case?