I have the same problem on a raspberry pi3b+. Sound system works fine. Spotify connect, bluetooth all shows me as connected and “playing”. But, alas, no sound. I even tried a older version of BalenaSound thinking it might be a bug in the latest version, but no cigar.
Outputting sound via headphone jack, logs shows that output as being selected. On reboot I hear a slight crackle in the speakers proving the jack to be powered, but no sound is coming through via bluetooth, airplay or spotify connect. Help greatly appreciated.
EDIT: This is a fresh deployment made today, As this is my first time trying out this project.
EDIT2: I actually managed to get it to work after making a few modifications.
Adding the following device variables and performing a full reboot seems to have fixed the issue.
Source of the variables found here: balenaHub - IoT embedded device apps, edge computing resources, and developer tools
I tried using RPI_HEADPHONES earlier with no success, So I cannot be sure if it was multiroom or audio output selection that was messing with me. I’ll test more at a later date.
AUDIO_OUTPUT RPI_AUTO All services
SOUND_MODE STANDALONE All services