Occasionally occurring issues are so annoying. I lived with these issues for years before becoming able to reliably reproduce them by accident and thus making a good guess on the cause:

My system would randomly freeze for ~5 seconds, usually while gaming and having a video in the browser running a the same time. Then, it would reliably happen in Titanfall 2 and I noticed there were always AHCI errors in the Windows logs at the same time so I switched to an NVMe drive.

The system would also shut down occasionally (~ once every few hours) in certain games only. Then, I managed to reproduce it 100% of the time by casting lightning magic in Oblivion Remastered. I had to switch out my PSU, the old one probably couldn't handle some transient load spike, even though it was a Seasonic Prime Ultra Titanium.