It could also be thermal issue as well right? I have 750W PSU, and I’ve been getting shutdown like this even when my PC was all brand new. At the time, I was building a small form factor PC, so I use mini-ITX motherboard in a compact case, and all my hardware are running at stock speed.
Usually what happens before a shutdown was a high increase in RPM on all my fans (CPU, Case, GPU) to full power, then suddenly the power just cuts then reboots. It always happens on most games I play. And everytime it does, my PC case is boiling hot…
Then since I got so fed up with it, I bought a larger case, and slapped every hole with a fan, so that it has a larger room to breathe and airflow that goes through all the components.
I have to say that I’m getting shutdowns a lot less frequently. I still get them from time to time, but only from very high-demanding AAA games running at Max settings at 4K. Even so, it only happens from time to time. And this is coming from the exact same hardware, same PSU, same everything. I only upgrade my CPU cooler and fill up the case with case fans and proper airflow. And I’m getting less shutdowns like these.
MSFS isn’t an exception. This is a very demanding app after all. Usually what I use is to underclock the GPU only by around -300 MHz, that usually stabilise my system, even if I’m losing a few FPS.