www.makemkv.com

No...I played the Valerian UHD backup (AVCHD folder) direct, local from a USD drive.
I didn´t test the .mkv I made from Valerian yet, but searching for those artifact scene
on the my PC, I didn´t find them again!? I have to test the .mkv via the Oppo first to be
sure. If the .mkv will work without a problem, well that is just kind of a solution . Because
if I have to do so on some UHD discs, I will lose Dolby Vision. The Oppo203 ist able to
play the UHD backup as a folder structur, just copy all UHD folders under the AVCHD folder.
Everything without any jailbreak or hardware modification and on the final Oppo firmware
incl. Dolby Vision and HDR10+

What´s for sure....there is a problem with this Valerian disc I think.
Men in Black International UHD 0% errors on the backup, good speed under 1.04 MK.
0% errors when backup or generating a .mkv with two standard 1080p BluRays.

So right now, I feels like a stable setup...of course I need to test more UHD discs.

Success ripping Brightburn and Pikachu UHD complete backup
No errors or anything...

So I´m sure there was an problem with the Valerian UHD disc and my setup
should be stable.

Success ripping several UHD´s.
Found one disc (Venom), where I ran into the same hash check errors.
I found two tiny scratches on this disc and just used some toothpaste to polish
those scratches. Believe it or not, after this cure , I also ripped successful this
UHD without any errors