Media controls on Steering wheel

[J45P]

Hello
I'm after a little bit of advice, our XC90 (T8 2016) which I've had for a month has developed a strange fault where the buttons on right side of the steering for controlling the media, left and right buttons and the centre buttonno longer respond once the ignition is in position 2 (engine on / running / electric on ready to go).

As soon as you switch off and are in position 1, where the radio / lights etc are still on the buttons respond.

I've reset back to factory settings in the menus and no joy, initially when this happened I could get them to function by changing the driver display from map to media or to show nothing and then back... but now nothing seems to help

Strange thing is its intermittent as advance forward will randomly work but not back. Volume up and down seem to work fine although the first time it happened the Volume down button stopped as well.

Is this the SWM issue I've read about on some posts or am I being thick and have missed a setting / fuse somewhere?

Thanks
J45P