Thanks for the advice. I got my GT King Pro to boot from the default Android OS. It looks like only the images that does not include Desktop environment would boot. Others builds (5.7 and 5.9 kernel) with Desktop would just not boot. Blank screen.
I've seen some people tried this on a Beelink GT King / Pro. How do you get it to boot from the default Android OS? I've tried to hold the power button to bring up the switch OS option, but nothing happen if I click that. I followed the instruction on the first page, and used a DTB from CoreELEC.