Hi,
I have Libreelec (tried various versions) on a Raspberry Pi 3. I've added a IQaudIO DAC+ audio card. I find the USB keyboard volume controls, and the mute button, have no effect. I have checked key mappings, and they're fine. Somewhat bizarrely, I've found that I can control the volume via Kore from either my phone or from a web browser. Same applies if I just use the built-in audio out from the Pi itself.
What am I missing?
Thanks,
Steve