Mouse sensitivity change in League loading screen. [Gameplay]

So I just started having this problem today. I recently bought a new gaming mouse, so I upped the dpi, and lowered my mouse sensitivity in Windows. Now, every time I start league (and not any other game) my mouse sensitivity is changed back to the windows default (6) and I have to go through the control panel to change it back. I happens about halfway through the loading screen, and has happened on the Poro King gametype and custom games.