[2021] Mouse Glitch (ADS / Movement)

For the last few days, I've had issues with my mouse that feel somewhat similar to the raw input bugs at the start of the season. These occur randomly (the problem is not constant, but appears every once in a while, sometimes frequently).
When I ADS (by holding right-click), instead of consistently aiming, my weapon will occasionally flicker out of the sight when the bug occurs (as if I was releasing right-click for a split second and then holding it down again). When this occurs, it usually does multiple times over the course of 5-10 minutes. The same flickers will sometimes occur with my mouse movement during that time period. Visually, the bug can be compared to extremely fast jittering of the mouse hand.

I have so far tried turning VSync off and on again, as well as leaving it off, and have also turned off raw input.
This bug makes it impossible for me to properly compete in higher ranks, so I would greatly appreciate some help.