when you're playing in the 1.12 and change to the 1.13 (any of the snapshots or pre-release) the sensitivity changes it's speed, but not it's sensitivity level.

i have my sensitivity level in 46%, i'ts going well in 1.12.x and oldest versions, but in the 1.13 it decreases the speed, so you have to change it to a superior level. and if you want to go back to the oldest version, the sensitivity level increases as you change it in the 1.13 version