2021 Sundancer 320 electronics spontaneously reset. Can't see fuel level now.

[KnivesAndShallots]

Hi all - I have this new boat, and have used it several dozen times so far. The other day, I arrived at my boat to find that the electronics have all been reset to default. When I powered up, it asked me to initial set up everthing - i.e., I had to indicate the number and type of engines, add the GPS receiver, re-set up all my displays, etc. It took about an hour to get everything back to the way it was, but I could not figure out how to re-add the fuel level monitor. It's just reading 0% now (although the fuel consumption rate does work).

First, anyone have any idea why this happened? It was plugged into shore power the entire time, so there's no indication the batteries died.

Two, anyone have any idea how to re-add the fuel level monitor?