If it is anything like me 2010 XC70, both the part numbers need to match and the unit needs to matched to the car in the software at a dealership . Volvo in their infinite wisdom,. again, at least on my '10 XC70, made it so the radio can't be easily replaced.
Same thing happens when my amplifier gets flooded aftr replacement, ifound the solution... under the passenger seat , check the fuse box replace the 40amp fuse on number 24. And it will work back to normal.. :)
Hey Josh. I have the exact same issue. Mechanic quoted me £1000 for a replacement screen and new software. Looking to fix it myself. Did you manage to solve the issue?