Ideas
The potential fix is a lie.
When you launch the game you got a chance that the button that make you stutter change.
All known button are WASD and 1-2-3-4 also the grenade button and kit button. There is still no fix and it change randomly everytime you launch the game.
It's unplayable. I tried re-install, driver, javelin, game, overlay, personal anti-cheat, monitor. We gotta wait for EA to acknowledge that the game is unplayable. How much are we gonna wait is based off if DRUNKKZ3 actually try to play the the new update this weekend rather than passing time with his family and or having a productive useless social life for new years.
https://steamcommunity.com/sharedfiles/filedetails/?id=3626300845 - read here)
In short, the first 3-4 keys you press on your keyboard after launching the game are guaranteed not to reproduce this bug until the next reboot.
So, press W A D C keys as the most necessary ones in conjunction with mouse movements.
The remaining buttons will still be laggy, but not all of them.
For example, on my first press W A D C, the buttons Q E are same protected from the bug, at least.