Intel NUC - no audio output

I am completely new to Balena-sound so have no idea how to debug but I have experimented. I have 2 old NUC computers DN2820FYK and rather than send to landfill - using Balena-sound would be a great use.

I have made a fleet, installed Balena-sound and spotify will play to them BUT…No sound is output: frome the 3.5mm jack OR via an HDMI audio extractor OR via a USB headset (I assume essentially a USB soundcard).
I have installed the NUC’s with these versions and BOTH exhibit the same problem (no sound output). I assume this is the configuration of the sound hardware on an older NUC platform but no idea how to sort it out (if possible).

NUC version :
balena-cloud-balena-sound-intel-nuc-6.2.4+rev2-v16.10.3

Generic Version:
balena-cloud-balena-sound-genericx86-64-ext-6.2.4+rev2-v16.10.3

The device logs show
2024-12-31 12-08-53.108 [Error] (Connection) Error in socket shutdown: Socket not connected

2024-12-31 12-08-54.109 [Error] (Connection) Failed to connect to host ‘localhost’, error: Connection refused

I would be grateful for any help and happy new year to any readers!