Imported h.265 8k messed up

[rokki123]

First time i encounter this problem.

Working with h.265 8k 29,97 video.
Original media outside of premiere looks fine.
When imported in Premiere Video is messed up. Jumps in the middle of the clip back to the start or stuttering, jumping.
Proxies look fine. When switching between proxies und original - they are not in sync. Export confirms, it only exports messed up video.
Encoder also only grabs the messed up video when trying to encode otherwise.

[Richard van den Boogaard]

Which version of PPro are you running? CC2017, 2018 or 2019?

Do you have the latest drivers for your GPU? If not, please install them from the Vendor's website, don't rely on your OS-update cycle.

[rokki123]

CC2019    
All drivers are up-to-date

[Stan Jones]

What graphics card? What specific driver version?

[rokki123]

1080ti - 416.34

[RFS2]

I have a somewhat similar difficulty : I have no problem to import 8K material coded in HEVC, but the export in the same mode is very much degraded. What settings should I use to preserve the original quality?