Camera Stuttering Visual Slitches

Whenever I move my mouse, the camera movement looks like it's stuttering. But when I move via WASD, it's completely smooth. This appears to happen when I have OBS open, have several applications open, or I'm watching a screenshare on Discord. It only stops in windowed mode. But I don't like playing in windowed mode. I have tried updating graphics drivers, changing fullscreen optimizations for my game, I don't know what else to do.

I'm not sure if it's a mouse problem,
A monitor problem,
But whatever it is, it's extremely annoying.