Currently, the native Linux build of the game is roughly 3 versions behind the Windows release, and is not only outdated but nonfunctional, since input breaks completely in fullscreen mode and generally on Wayland (default window system for anything not running SteamOS' custom X11 build). The easiest way to fix all of this is to simply enable custom compatibility tools in your settings and switch to Proton7/ProtonE. Both of these work near-flawlessly and have functional multiplayer, with a few minor bugs that I haven't been able to narrow down fixes to with launch options. If I do, I'll edit this post.