I appreciate all of your help on this techjunkie. This issue is beyond frustrating.
When I play it back, in an mkv container, I am still seeing distorted color, using the same exact same modifications you made to the file using FFmpeg version 4.2.4 & FFmpeg version 4.4
Here is the same exact file but this time in an mp4 container. For me, this plays back perfectly:
No matter what I seem to try, I still get the HDR color distortions when playing back HEVC in an mkv.
Mediainfo readout, of the mkv file I tried:
Default : Yes Forced : No Color range : Limited Color primaries : BT.709 Transfer characteristics : BT.709 Matrix coefficients : BT.709