In rather demanding games and only games , such as Astroneer, Helldivers 2, Ready or Not, and more, my system will soft-crash. I say soft-crash, because the fans keep spinning and audio continues for a few seconds longer, but both monitors stop receiving a signal - the only way to recover from this state is to restart the PC.
I've tried submitting a bug report on the Nvidia forums, but they've been less than helpful. In truth I'm not 100% sure it's a proton issue, but the only games that crash like this are running via proton.
Attached below are the proton logs for Astroneer running with proton experimental:
steam-361420.log