4K 10bit output issue in Zidoo x10

[uhdtv]

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?

[futeko.com]

Please confirm whether you have Zidoo Z10 (2018/19 version) or Zidoo X10 (2016 version)?

[uhdtv]

It is Zidoo X10. I purchased in 2017.

[futeko.com]

See here for debate and explanation of this issue, it appears to be a limitation of the Epson: http://forum.zidoo.tv/index.php?threads/issue-with-4k-hdr-bit-depth.7819/

[pcristi]

Epson TW 8300 is 1080p (4K Enhancement) with HDMI 1.4b, only 2160p 8bit supported using pixel shifting.
For 2160p HDR content play in native 2160p 10bit color depth need a native 4K projector/display with HDMI 2.0/2.1 inputs.

[uhdtv]

The thing is that If I change the settings in media player as 2160p@60, 10/12bit YUV4:2:2 or YUV4:4:4, the projector info falsely shows colour depth as 12 bit (even if my media player setting is 10 bit) although my media player shows 8bit colour depth output.

http://4k.com/projector/epson-5040ub-review-4k-hdr-projector/
You can see that it is actually capable of outputting 10bit colour at 4K@24 from port 1 (HDMI 2.0).