Music – RPi4 – "No Speaker" symbol – top right corner



Hello, I am running Kodi 19.1.0 on LibreELEC 10.0.0 on a RPi4 as a music server with an Allo Digione signature SPDIF output on the GPIO header. Music is .flac on an SSD.
This has been a solid performing system for several years. Worked fine Tuesday. Wouldn’t play Wednesday, but it was late so I went to bed rather than make an dumb mistake when I was tired.
To clarify: the display looks like the streamer is playing, but there is no signal to the DAC.
I suspect a problem with the Allo output or associated.

I started troubleshooting today, and noticed that there is what looks like an international “No Speakers” symbol in the top right corner of the Pi screen.
(I don’t think it was there yesterday, but I might have missed it…)
Red circle with a red speaker in it with a red line through it.
I couldn’t find this in the FAQ.
It looks more ominous than any mute symbol I’ve seen…

Is Kodi/RP smart enough to know that an output device has an issue ?

Thank you for the help,
Bil Sheckler