I can not imagine what kind of situation would cause the settings to change to what you experienced.
I have been a circuit designer and an embedded software engineer for over 25 years now, and I can assure you that having situations happen that no one can explain is, if not routine, then at least a frequent enough occurrence that there is a highly technical term
for the phenomenon. This name is:
And I think it has happened in this case (Floyd used to work for Cray -- he should know all about this).
(Incidentally, this is why Brett Buck got the rule passed about restraining electrics any time the battery is plugged in, and why I was doing my best to stand right behind him nodding my head "yes". You can
design electronics and software in a way that minimizes the weird chit even to levels low enough that people feel confident running airplane primary flight control surfaces with 'em -- but doing so drives up the cost of development, and the less weird chit you allow, the more it costs.)