Try running in dev mode and display msfs frame rate tool. Run experiment again and check line below the frames to see if you flip from GPU limited to main thread limited.
Ive noticed something odd but not sure if it’s placebo… for example I live in Europe and if I fly in Europe during my daytime hours I notice poor performance but when I fly in the US during my daytime hours which would be late at night in the US I get good performance which would appear to be a network issue.
now I fly US mainly as servers loads seem to be a bit quiter during my time of flying.
again, this may not make sense just a observation.
I see that your cpu is very high, my i9-11900k cpu and rtx 3080 also produces stutters, at high frequencies, and a good stabilization in processing is recommended, I tried many configurations, both in cpu ( 5.2 - 5.0 - 4.9 - etc) and ram (3600 mhz) and for me a stable configuration without stutters in cpu = 4.2 and Ram (3.2). I recommend that you take some time to perform performance tests as overclocking is not that good for the game in general, I hope I have helped you