Guys

I had an aux input added to my stereo in the Vogue a few weeks back (JLR touchscreen)
Since then, I have had no audio on the radio itself at all, but this didn't bother me because I use an Alexa auto with the aux input. However, today the aux input has lost sound too.

So, the screen boots up as usual, beeps when pressed etc. No sound on radio or aux but CD player working perfectly.
I have asked the guy who fitted the aux but meanwhile I'm looking into what I can check myself.

The amp etc is dry and still works fine on CD anyway. I'm wondering if it might be a faulty radio receiver module, because (I think) the aux comes from there too?

Any ideas gratefully received.

Thanks.