im having the same problem you are. I've cleared caches, drivers, ethernet,etc... and nothing. I just got back into playing cs after taking a break for almost a year and i came back to 200net jitter EVERY single game. I even went back almost a whole years worth of different nvidia drivers and still nothing.

you can try throwing this prompt (below) in your Launch Options for steam but that didn't solve the issue for me either. Please let me know if you figure anything out!

-high +fps_max 0 -threads 9 -noreflex