[2019.2, 2020.1 Alpha] Mouse scrolling does not work in Scene editor/anything with a scrollbar

Hello there,

I just recently started playing around with Unity and started off by checking out the Tutorials, where I had to install version 2018.3 for the tutorial of choice. In that version, scrolling was fine and working.
Then I wanted to use some newer features, and also the UI is nicer, but I noticed that I couldn't scroll anymore. Anywhere in Unity. Not in the Inspector, not in the Scene view, not in the Project view, not when there was a scrollbar shown anywhere.
This problem occurs in versions (that I tried out) 2019.2 and also the 2020.1 Alpha (currently installed is 14).
I'm running on Archlinux x86_64, use i3 window manager and have a Razer Mamba Chroma (wired). The mouse works everywhere except in Unity. Therefore I guess (and hope) it's not my mouse.
It's not a world-ending issue, but it does suck a little not being able to scroll at all.

I couldn't find any other post that describes this problem, so I made a new one. I hope this was enough information, else I'll provide more on request.

Hope there's a solution.