So... my Incontrol media centre can’t read the music library when I connect via Bluetooth... it can when I attached a lead and play via iPod.. I have tried with various phones with no luck, so I know it’s not a phone issue..

any ideas, 

Hello Roger. I am non the wiser about phones and what the can and cannot do. Some time back Samsung did an update of their systems (Android) and many XE owners found that they could not connect to their car anymore for Incontrol or any part of it. Then JLR blamed Samsung and vice versa, or so it was mooted. I bought a new Apple IPhone and all was well again. One thing I have noticed with it when charging is that I have to use specific leads and it will not charge from the USB port on my PC. The older Samsung phone will charge with any lead. You may have heard that the NHS Track and Trace won't work with older phones, so I wonder if that operating system worked on the old system that JLR used, whe nearly all phones worked the Incontrol. You have the same year car as me. Right,  after all that prattle, I wouldn't be surprised if there is something in the 2015 system that does not connect to that part of Bluetooth in the same way that the Incontrol wouldn't connect with the old operating system of Android.