Hello @Syvar, using Proton with NTFS is known to be finicky and there are several issue reports tracking various issues with Proton interacting with NTFS partitions.
The general recommendation is to use a linux native filesystem with Proton.
Closing in favor of the older issue reports.
Nothing extracted yet.
To be more specific, native Linux games seem to work perfectly; only games launched with Proton have that issue.
I have followed this guide: https://github.com/ValveSoftware/Proton/wiki/Using-a-NTFS-disk-with-Linux-and-Windows and the issue persists.
I have also tried reinstalling both the games (Alien Swarm, Alien Swarm: Reactive Drop and Hades) and Steam.
The thing is that I moved AS:RD to a btrfs partition and it worked but since I use Windows a lot and I can't just wipe my entire drive just now I prefer having the games installed on that NTFS partition.
System specs shouldn't matter but I will list them anyway.
CPU: Ryzen 1600X
GPU: AMD RX 580