I’ve just purchased an Arc and 2 One SLs to connect to my new Sony Bravia XR55A90J TV.
When using the tv as the source, I only get sound from the Arc. I can’t discern any sound from the Ones.
When I play music via Airplay from my iPhone though, the One SLs play too and I get great surround sound.
The Arc is connected to the tv via the HDMI eARC port and via Ethernet to Wi-Fi. The Ones show as connected in the Sonos app.
I’ve used Trueplay a number of times and have disconnected and reconnected the Ones but nothing changes.