This question has been asked previously in a slightly different context, but does not seem to have been answered. I am using LibreELEC Official version 9.2.3 with sound card M-Audio Audiophile 2496. My audio amplifier does not have a balance control to compensate for room acoustics, so I installed Multimedia Tools to use alsamixer to provide that function. It works perfectly, but the settings will not survive a reboot.
Invoking alsactl store 2 requires the directory /var/lib/alsa to be created. It then writes the file asound.state in that folder - so far all as expected. However, when the system is rebooted the new folder ...../alsa is no longer there, obviously along with the asound.state file. I cannot understand why the folder should be deleted, but is there some method of making LibreELEC retain and read the alsamixer configuration on start-up?