Out of the box the game has a desync issue as previously reported.

This seems to be a general issue on Linux for some games with vc_redist.x64.exe

To fix this issue I did the following:

1. Install Cabextract if you do not have it installed
2. Go to the game's system32 folder (steamapps/compatdata/1100420/pfx/drive_c/windows/system32 in this case)
3. Open terminal in the system32 folder and run the following command: wget https://download.microsoft.com/download/9/3/F/93FCF1E7-E6A4-478B-96E7-D4B285925B00/vc_redist.x64.exe
4. Run the following command afterwards in the system32 folder: sudo cabextract vc_redist.x64.exe
5. Run the following command afterwards in the system32 folder: sudo cabextract a10
6. Close terminal

Running these commands using sudo should return no errors

Install needed:

1. Cabextract
2. Protontricks (optional but nice to find game folder name)

Proton version: Proton 8.0-5

Tested multiplayer and worked for 30+ minute game.