I received my code 50 today, when switching the amp on the display never changes from 'Marshall Code'. turning the preset knob won't change the display either, accessing the amp wie the app works. I also tried resetting the amp which won't get me past the 'Marshall reseting presets' screen. Any suggestions would a firmware update help?
It sounds like your CODE could be faulty. I would suggest taking back to your retailer for an exchange of a new unit.