Hello Icittandini,
As long as you are at firmware version 25.002.03.003 or higher and using port 445, NTLMv2 authentication is supported and should work. The latest general release posted on Xerox.com contains this fix, you can obtain the latest general release here. Directions on how to upgrade the firmware on your device are located here.
If it is not working for you, please contact the Support Centre for assistance.
Hope this helps.
Thank you,
Tim