Unfortunately, it often does. I've run into this on both AMD and NVIDIA hardware.

> That shouldn't happen on a modern OS

They're running Ubuntu.

Care to explain? Sorry I don't use ubuntu but the claim that the OS just straight up reboots during normal operations is particularly concerning.

It's completely normal for Linux operating systems, and in fact even most others (even Windows and Mac under certain loads), to choke and fail under resource exhaustion. I've experienced it the most with Linux though, but I've done it to Windows and Mac too.