Are you in 10-bit mode? --> the 2018.02-1 update has the “echo “444,10bit” | sudo tee /sys/class/amhdmitx/amhdmitx0/attr” command build in?! i have this also in the rc.local!
Is the film HDR? --> yes!
Did you run this as root? --> yes!
Is your device up to date? --> i have installed the 2018.02-1 (not the 2018.03-2 update) - does the command " sudo echo round1 >/sys/class/amhdmitx/amhdmitx0/debug" also work with this build?
Does dmesg show feedback after you run this command? --> what feedback? After type in this command the only feedback is a new line in the shell…