I am using Zidoo x10 and it has latest firmware update. I am using Yamaha AVR RX V681, Epson TW 8300 projectors - both of them support upto 12bit HDR. But when I play any 4K HDR content, it outputs 8bit colour depth at 2160p resolution. It outputs 12bit when the output resolution is decreased to 1080p. Colour looks much better in 1080p, 12 bit colour depth than 2160p, 8 bit colour depth. Why is it happening? How can I watch 2160p HDR content in its native 10bit colour depth?
Most likely is your HDMI cable, not enough bandwidth or it's too long (like mine). I have 10m hdmi and I have similar problem like you, I'm getting colors banding when watching 4K HDR content, not that much, mostly noticeable in the sky. So for that I'm looking to buy optical hdmi (more expensive), which should solve those problems. But I'm not 100% sure if the player itself is causing this, I will have to try it with shorter cable or with optical hdmi.
