[Tamas.Toth.ebola]

Is the 8-bit 4K version much lower bitrate?  If not, then bitrate is not the reason for the 10-bit 4K failing.  If 10-bit 4K HDR plays back in other streaming apps (Netflix, Amazon, Disney+, etc.), then it's probably also not an OS or hardware limitation.

Now I have no time to check the bitrate but the 8bit file is 4GB, the 10bit is 5GB. Both of them is exactly the same ~50 minutes video. So from these data, approx.:

• (4×1024×1024×1024×8)÷50÷60÷1024÷1024=10.92Mb/s
  
• (5×1024×1024×1024×8)÷50÷60÷1024÷1024=13.65Mb/s
  

Not so high, in my opinion. Neither the overall, nor the difference.