Severe color banding issues due to Apple TV 4K's 12-bit (instead of 10-bit) video output

Hi.

I have severe banding issues when viewing 2160p24 HDR10 content using my Apple TV 4K.

Here is as an example an image from Blade Runner 2049 from the iTunes Store, at 1:42:45

It looks worse IRL.

It looks OK as long as I select 2160p60 or 2160p50 instead of 2160p24 as a video resolution, and have never enabled 4:2:2 chroma subsampling (if I have the Apple TV knows it can push 12-bit video at 2160p50 or 2160p60, until I reset video settings).

That is the case where the Apple TV chooses the only possibility that fits into the "low" HDMI bandwidth of 10.2 Gbps: 2160p60 (or p50) in 10-bit with 4:2:0 chroma.

This looks exactly like issues that some UHD Blu-Ray Players had because they output 12-bit videos when some HDR10 TVs can only understand 8-bit or 10-bit video (which is understandable since and HDR10 video signal is only 10-bit).

As an example, there has been an online petition for this very issue for the Panasonic DMP-UB900 UHD Blu-Ray Player : https://www.avforums.com/threads/panasonic-dmp-ub900-player-severe-banding-macro -blocking-issues-with-12-bit-4-4-4.20428…

... and Panasonic added the possibility to choose 10-bit video output instead of 12-bit video output in a firmware update :-)

Do you have such issues (which you can see for example in blue skies showing bands of color) with your TV and an Apple TV 4K?

Do you have ideas on how to have this corrected by Apple?

(I have already filed a bug report)

Thanks in advance and have a great day!