I have recently bought a 2021 superb the radio signal is absolutely rubbish can anyone shread any light on this issue it’s poor on every channel 

Are you getting any stations/sounds at all through DAB?

Yes for a short while then it wavers it’s comes and goes 

In my 2018, if anything is plugged into the 9v sockets then this degrades the signal.  If you have anything plugged in this might be the problem.

I’ve plugged into the 12v socket near to the ashtray (which I don’t smoke) a anti interference duel charger and it seems to have done the trick

thanks every body for your help