I run kodi through libreELEC on a raspberry pi 4.
An interesting gotcha is that on the raspberry pi 4 there are 2 x HDMI ports allowing for 2 screens at once. Quite cool! But when you install the libreELEC install on one HDMI port and then replug into the other, you won’t get sound. There’s no function in the gui to change this and no real google fu will lead you to the fix.
After stymying me for about 20 minutes I tried plugging the hdmi port into the original port and voila! all worked fine.