If you want direct play of the file, play around with different clients. Encoding 4k can be taxing on a system. Some jellyfin clients just don’t support the media format for direct pass through.

Looks amazing, but I really wanted amd so I could make a chimeraOS gaming console

Blew up 4 years ago https://www.youtube.com/watch?v=2svOtXaD3gg

I think you should talk to a professional. That’s what they’re there for.