I am using the Android TV 7.1 Community Build Image [eMMC] by ayufan image (android-7.1-rock-64-rock64_atv-v0.3.13-r115-raw.img.gz) and Kodi 19 from Google Play Store and all sound that I tried works perfect, but for some reason the HDR is not working.
My box (Rockchip 3328 - Popcorn Hour Transformer) connected to my Denon AVR-X2700H via HDMI Cable (2.1), I will try to get an SPDIF cable and test how its work with latest LibreELEC .