when I start up a beatmap my mouse goes to like 0.20 sensitivity (feels like it) I normally play on 1.3-1.4 and I really hate not being able to freely move my mouse around when I start my beatmap
When did this start happening? Have you tried restarting your PC ever since the issue started occurring? If not, give it a try, and also make sure you haven't accidentally changed your mouse's DPI.