www.makemkv.com

There is also the possibility to install MakeMKV as a flatpak if you want to keep it simple.

That is quite interesting.
Does this mean, that in the future it will be possible to decode UHD BD simply like a Blu-ray Disc without having to send in a dump file?

Since today its working. Thank you very much!

Sent in the dump for High Tension.

just as a tip you can also just use MakeMKV as docker in unraid.
Then you don't have to use the VM.

I stumbled across this because I had the same problem.
I have used MKVToolnix. To do this, select "Output" Split mode "Before chapters". At Chapter numbers write 5 into it.
Then just press Start muliplexing.
After that there is no more black screen at the end.