Just a quick update on my 50H8C bought a few years ago.
HDR was underwhelming for the most part, it had issues with my Xbox One S and Netflix.
It was until I got the Denon X3400H, which fixed the HDR issue and HDR works great, looks gorgeous but still limited with the number of nits it can produce, but I can tell when HDR is on.
Also for my BR HDR rips, I'm using the Minix Neo U9, using libreelec and changed the settings to 10Bit 4:4:4, HDR works great and I can tell a difference.
Hope this helped someone that has HDR issues.
Overall, this TV was worth every penny after I got a better AVR, but it's about to retire...