Streaming BBC Radio 3

[Wwhattam]

I have the playlist for BBC Radio DASH visible to my Control Point (using HiFi Cast at present) and I see the following:
* HiFi Cast shows BBC Radio 3 playing.
* My renderer (Yamaha R-N602) shows [R3} BBC Radio 3 on its LCD screen.

Yet I have no sound - I have tried different volume levels with no success.

Note 1: when I tried modifying the stream with acc:L16 and also acc:wav I got no response from the renderer. So just the straight unmodified stream should be the correct one.

Note 2: The Yamaha R-N602 does have MusicCast and can play internet radio with no problems. I don't believe that this could be interfering with what is posing as a music stream.

Any advice?