Between playing a match and going on to the next, my sensitivity changed. It dropped by about half.
The setting in game and Windows settings remain unchanged, but I use a rig to match sensitivity between games (to get it exact). It works by strapping my mouse in, a bolt and notch fix it to a line (so orientation and distance is exact each time), a spot is picked on a wall, and it’s slowly dragged to the marked line where it should make a complete 360 degree turn… I mention all this because now it faces somewhere around 180 when it should make a 360, settings remain unchanged but there was a sensitivity drop.
I use a M510 mouse (no configurable dpi setting), acceleration is turned off, and I’ve never had this problem with any other game. The BIG problem is that it also effected changes in other games.
EDIT:
Issue found.
I found the laser of the mouse was unsecured, found that it can move a little bit and “wiggle”. Chances are this is what was causing my issue.
Resolved; hardware (mouse) issue.