If you want to change your sensitivity on 1.8.3, go to C:\Users<yourname>\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\SystemAppData\wgs\
In the WGS folder, there’s a folder named full of digits (mine is “0009000007C3FE07_00000000000000000000000069F80140” go figure). Inside this full-digit-folder, there are one folder per peripheric you have in MSFS. The naming is also not guessable. Open each of the folder and look into a file without extension which are actually .xml format file. Open them with notepad for example.
For example, the first line of my file C:\Users<MyName>\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\SystemAppData\wgs\0009000007C3FE07_00000000000000000000000069F80140\1BEA9A531B744962BB6D48B1401059AD is :
Before patch 1.8.3, I set -60% on X, Y axes and -50% on the Z axe.
Remark : thanks to Nirgal76 on a french forum for sharing this tips.