Same here. Stable for days then without any known antecedent it would gracefully exit. There is no sign of a crash. I just updated to their latest build and am running the watchdog to see if anything happens that I can record or fix.
I too went away for a couple days and of course, came home to a dark house and I too had my stomach get upset because I know this will overtake my life to figure out the issue.
The fun of automation....