I have had the same issue for two years and it has progressively gotten worse. I use Ubuntu and have very similar hardware. The piece of hardware I have traced my issue to is the 5700XT. I ran some Phoronix stress tests on my video card and reproduced the same crashes. I also looked up the MCE errors that were being produced and they also pointed towards that card. I’ve given up trying to fix it and I will be purchasing a different graphics card soon.
To diagnose your issue, do you see any MCE errors when your system reboots? If not, run journalctl and grep for ‘MCE’.
Nice. What’s your main in Grim Dawn?