Presets gone + nozzle size error
Have been using the printer (kit) since January with no problems, but the other day it restarted by itself as I was preparing to print something. When I went back in to finish starting the print, the presets I had specified in PrusaSlicer (PLA, PETG, etc.) were gone and instead there was "farm 250/80" and "nozzle 250/0." When I set the temperatures manually and tried to start a print, it told me that the nozzle size was wrong (I was printing at 0.20mm which I've previously done with no issues).
I restarted the printer and tried to go through the calibration process again, but it got stuck at First layer calibration — the extruder shakes without moving along any of the axes and it's clearly putting stress on itself. Not sure how to proceed. Does anyone have any idea what went wrong in the first place or what I should try next? Thanks!
Firmware is up to date.