Meo
4
Could you try going on official server for a bit and see if the problem is present there?
Did you try “verify file integrity” of the game?
Did this problem start suddenly or maybe some software/hardware change has happened?
Could be a bug but…
A VERY viable option: your mouse is “near end of life”. I have see several… rodents… start misbehaving under certain conditions, before slowly shutting down overall (left button obviously being most used)
EDIT: small typo