[wesk05]

Thanks, of course now I recall that thread/post . So, just tested both the Cb & Cr light gray patterns in the HDR10 folder...
...and the results look very similar, if not the same. Zidoo's looks cleaner, but both look closer to the 8-bit screenshot you posted above. Not completely solid gray as it should be.

I forgot to mention, try the non-HDR ones in the BT.2020 folder.