My setup:
Beelink mini S12pro with LibreElec 12.2 connected to samsung soundbar Q600c with HDMI. Passthrough in AUDIO section enabled. Soundbar conected to samsung TV S90D HDMI via eARC. (Newer samsung TV's do not have support for DTS audio formats so i could not connect LibreElec mini PC directly to TV using eARC and using audio passthrough.)
Problem I was deailing with:
After playing video with DTS:X audio, I would not be able to get audio on any video playing after.
Solution that worked for me:
Change LibrELEC audio setting
Keep audio device alive: Always
to
Keep audio device alive: Off