ps : Is it a kernel problem that doesn't manage HDMI and analogue on the motherboard?
I think the driver is missing at the kernel:
Code
Dec 03 17:49:09.953126 LibreELEC kernel: ALSA device list:
Dec 03 17:49:09.953148 LibreELEC kernel: No soundcards found.
Our devs usually add available Linux drivers, it just takes time.