Are you doing anything like network mounts? I’ve had freezes happen when home was mounted remotely. I’ve also had freezes before – though not recently – when doing extremely intensive I/O operations. I’ve also seen it with failing hardware, but I don’t remember what hardware was failing specifically (if we ever found out – that was an always-on display system at work, and we might have just replaced it since it was ancient at that point…).
See if you can switch from GUI to console (either on the system or SSH-ing in). Usually the Ctrl-Alt-Fn keys switch between GUI and full screen console modes if you’re physically there to try it. If you can get in, you might be able to get some insight into what’s going on from logs, top, etc. while it’s happening.


















You can do something similar in English through sarcastic statements with inappropriately polite forms of address. e.g. saying “Well, excuse me, sire!” to someone with a sassy tone of voice should be interpreted as “I’m offended” or “I can’t believe you just did that, you asshole” or similar depending on context.