Djm-900 nexus written on panel doesn't match with display and other djm

Good evening, I hope this email finds you well! I'm willing to buy a DJM900 Nexus but it is second hand use. It plays properly, but on the display the names of the effects do not match the ones I intend to use. I updated the firmware and no luck. I checked online for any good practice advices. Nothing that could help me! Could you support and suggest guidance, please? My biggest is fear is that might not be an original. Do you reckon this is issue is because is a fake? Looking forward to hearing from you, have a great day! Kind regards, Luigi Imperato