when you aim with sniper scope you have exactly the same sensitivity on 0% and 100%? Report in forum and will see if someone else has this problem. I tested just now and everything works as expected.
EDIT: do you press SAVE after changing aim sensitivity?
I just ran the game, changed aim sensitivity and tried again. It seems to be kind of working. I dont know what the problem was then. Anyways thank you for your support and amazing job on the game! and im sorry if i caused trouble