Here’s my suggestion.

First, check your RAM with Memtest86+ or similiar tool. This is the first test because failing memory can and will corrupt your whole system, and it’s easy to test.

Second, if RAM is fine, check the logs. This is more effective then just guessing. Just copy-pasting possible errors to your favorite search engine usually points to the right direction. Archwiki has a nice tutorials about logs.

Third option is to test components one-by-one. Remove all unnecessary components, such as extra SSDs/HDDs, wifi cards, USB devices and PCIe cards. If it doesn’t help, test your CPU and GPU by running dedicated CPU and GPU benchmark tools. If you still get hangs, try with another PSU. If your components test fine, it’s likely a driver issue. See Arch wiki article on Nvidia troubleshooting for some tips about that.

Your last option is pure guessing. It’s the most time and money consuming way to debug with the smallest chance of success, but still many people prefer it. Most often issues like these are GPU issues, so it’s a good guess. However it’s still a guess.

I hope this helps.

Maybe try bleeding edge. See,

https://github.com/ValveSoftware/Proton/issues/3898

Acording to SteamDB, there has been no updates. I didn’t manually check all of the 355 depots though. I’d guess it’s either shader cache, corrupted game files, or a bug in Steam.