Mouse lag still no fix

Asked for a fix for the mouse input lag and all they said was to turn off overlays or close discord. Did both, even played in windowed mode and that didn't work. Turned off windowed mode optimization, nope. Nothing that anyone has suggested has fixed the issue. Sometimes the game will even move the mouse around by itself in random intervals or I just can't move it at all. All other inputs work fine. I need a fix so I could play this server slam, or I will be refunding the full game. Ridiculous