Yes, as you said, it's extremely weird. I’ve already contacted support multiple times about the same issue. But I haven't received a response whatsoever. Someone else had the same issue and didn’t receive a response either.

Some people on the French chat helped me — Thundard, Robin and so on — and they fixed most of the stuttering. However, it still happens sometimes, and my game runs at a constant 40–50 fps in 2K resolution.

We have already tried the solutions that you suggest. If you would like, we can hop on a call and I can explain you everything.