Well after some reading, this: Skin changes lost after a reboot - #79 by Yaffle seems to be the problem, similar symptoms and dozens and dozens of people complaining. But video and audio settings were reset as well, on all three systems. Kinda odd it happened on the same day, isn’t it? One of the system wasn’t even being used for a few days.
I’ve grabbed logs. But didn’t think grab-logs -A would automatically upload everything, including my personal information for everyone to see, without asking me first. So I chose to send them to Sam directly and asked him to check and remove the paste since the log contains sensitive information.