Erasing the flash drive is a drastic move really suited for when access to the flash drive is lost.
If you don't have a backup set of CSV files it can be a pain to recover from. Once you get a good set of files, copy them to a folder on your computer for when an experiment goes wrong and you need to backtrack.
If the joystick preferences get too far out of whack the file selector can be affected. The fallback values in the preference settings after a flash is erased will not work well for a newer FPS.
Attached is the prefs.csv file for new FPS units that are intended for use with a PC. That should get you in the ball park, then you can adjust things like brightness or volume.