Holding Shift+On on my HP Prime G2 resets all memory content [EDIT: happens again]

[anyfoo]

It also happens if I just press the Reset button on the back: Everything gone, except clock, calculator name, and theme (as far as I can tell so far).

I'm keeping it in that state in case there are some diagnostics to be collected that could help. I'm a kernel engineer by trade, so I'm not scared to do weird stuff. (And since it's essentially empty now anyway, I'm not scared to try things out in general. Don't worry, I have backups.)

EDIT: It's worth noting that I haven't used CK since I last formatted the device, and all my backups are in text form. So I don't think there's a connection between using CK and getting into that state, in my case.