I have been encountering a similar issue around the past few weeks, but everything was working before and I didn't get a chance to submit a bug report. For me, it looks like the graphics card was not responding after the crash (nvidia-smi hangs forever and Xorg.log said it was waiting for the graphics card - checked using an ssh session opened before the crash). I have downgraded my graphics driver to version 525.89.02, which resulted in a still alive Xorg when the games crash. After telling steam to use proton 8.0-2, it appears that everything works on my end. Can you please check if these steps help you work around the issue?
System Information (system hangs)
Distribution: Pop!_OS
SteamVR version: 1.25.8
Steam client version: 1682708537
Opted into Steam client beta?: No
Graphics driver version: 525.105.17
Proton Experimental (for games)
System Information (no issues)
Distribution: Pop!_OS
SteamVR version: 1.25.8
Steam client version: 1682708537
Opted into Steam client beta?: No
Graphics driver version: 525.89.02
Proton 8.0-2 (for games)
I get this in Subnautica VR mode and also in Vivecraft mod for Minecraft. I will be playing the game, the display will freeze and then go black. Both my monitors will go black and the system will require a hard reset ( power or reset button ) to be recovered.
SteamVR-2023-06-19-PM_07_43_07.txt
proton 8.0-2x1 2023-05proton experimentalx1 2023-05
Describe the bug
Steam VR stops display to headset on opening game and locks up the system
(This is my first time putting an issue here and I am unsure if this is a duplicate and I am unsure as to how to see if there is a duplicate issue)
To Reproduce
Steps to reproduce the behavior:
Expected behavior
Game opens, and able to play game or game crashes but SteamVR remains functioning
System Information (please complete the following information):
Screenshots

Additional context
I have been experiencing other issues with SteamVR (No Display at first, SteamVR setting another instance of itself as the OpenXR instance, no steamvr window, closing steamvr without using the window locks up system)
Systemd provided this coredump
Process 10713 (vrcompositor) of user 1000 dumped core.
Note: Commenters who are also experiencing this issue are encouraged to include the "System Information" section in their replies.