I have not seen any reports about unlock being firmware dependant
I suggest double checking the serial number etc is correct and re-generating the code (use DSER, not DSFR)
Enter it via SCPI command over telnet (easier than using the fiddly knob, and can copy/paste), should be instructions on the forum somewhere on how to do it.
Hope you enjoy using the new toy, and if you feel like voiding the warranty even more, then there are instructions on the forums about replacing the intensity/selection knob encoder with a detented encoder, and also a lot of people have swapped the fan for something quieter (I swapped the stock Sunon fan with a lower noise Sunon in mine).