Around 2020, Kyocera released a mandatory security firmware update for many ECOSYS models, including the M3550idn. This update:
If you are locked out, a factory reset through maintenance mode (Service Mode) can restore defaults, though this erases all custom network and address book settings. This typically requires entering the service code 10871087 on the keypad. Frequently Asked Questions - Kyocera Document Solutions kyocera m3550idn default password work
Users often encounter several issues with the default password: Around 2020, Kyocera released a mandatory security firmware
Print a configuration page after changing the password: kyocera m3550idn default password work
