Downgrading pango worked. Here is the command I used:
sudo pacman -U https://archive.archlinux.org/packages/p/pango/pango-1%3A1.44.1-1-x86_64.pkg.tar.xz
Typing on my keyboard while in game crashes the client on Linux. Running on proton is even worse - the client doesn't even open.
I have tried restarting, reinstalling, and moving the game to a different disk. None of these have worked.
This wouldn't normally be an issue as I play on the browser version but I've been wanting to test out a private server, and that's near impossible without the steam client.