I would very much appreciate your assistance. I’m running Ubuntu 20.04 on a 2010 Mac mini (dual boot via rEFind). Internal speakers work. Changed audio settings to HDMI, but I have no sound. I opened Alsamixer, and everything checks ( volume at full). I installed Pavucontrol, but after changing audio settings (Output devices) the issue persists. The Mac Mini is connected to a TV via HDMI cable, and have not experienced any issues on Mac OS.