It may have something to do with desktop/login/screen locking from my experience till now. Like suddenly starting when I login, while before it was off.
That would certainly be the first thing to try! And one of the first things that I completely disable on a production PC of any kind, even a laptop. If someone finds it still logged-in, unlocked, and showing on Monday when no one's touched it since Friday, that's good! It means it won't interrupt a show either.
Also, it splits the recording sometimes while I just want one file.
There's a setting for that. It's either in the Output->Recording settings or the Advanced settings. Don't remember which, and I'm not there at the moment to look.
But try the lock/screensaver first. Completely kill those (and don't lock it manually or logout), and see if that fixes the problem.
Occasionally, I've seen a desktop/window manager not have settings for this at all, but it definitely goes into an "idle mode" after some time. Counterintuitively, the fix for that is to install a screensaver, so that the installed one takes over, and then you can use its options to disable it.
