Stereo Illumination stays on when ign off???

[Avus4]

Hello everyone. Strange thing happening with my 2001 B5. The car has been garaged since last year until now and I have changed the battery for a fresh one. I have noticed that the stereo backlighting stays on even when the car is locked and goes off when you turn the ign key to pre start setting. Stereo works fine but this is illumination on business is puzzling me.



(It also did this with the previous tired battery on too.)

Any ideas gratefully received

Thanks Mike