Hi all!
I'm fairly new to cars and need some help

I bought a 2010 Mini One, however, the radio was dead. So, I decided to swap out the head unit.
The head unit I swapped it out with was a different model to the one that was originally in the car, but I didn't think too much of it as the radio was working and all the door chimes were working again.
I tried to connect to the USB port and the head unit didn't show any signs of USB being connected, although there was still power to the USB port.
I then tried the AUX and even that didn't work.

It only came to my realisation recently that the head units were slightly different, so, I'm assuming that I've installed the wrong head unit, as the one I replaced it with does not show up with a USB functionality or detect AUX?

I'm not too sure if the head unit I replaced it with needs to be programmed to facilitate for the AUX and USB functionality, or if I have to tear down the dash and swap the unit for the same part number and I wanted to find out what I need to do before buying another head unit again.

The original:
Model number: Radio 2 CD 73
Part number: 65.12-3455539-01



The replacement:
Radio 2 CD 3
Part number: 65.123450803-01


Thank you