Why can't I play songs through the AUX adapter cable in the 2012 Volkswagen Multivan armrest box?

Why can't I play songs through the AUX adapter cable in the 2012 Volkswagen Multivan armrest box?

I have a 2014 used XV, and the USB port in the armrest doesn't recognize P3 and P4 USB drives. The DVD also can't play videos. I don't have the manual, so I'm not sure if this navigation unit doesn't have these functions or if there's a malfunction.

The USB port in the armrest of a 2012 GLS can't charge your phone. Are there any other places to charge your phone?

Do any of you use a USB drive to listen to music? Does the USB drive need to meet certain requirements? Why can't the songs I downloaded on my previous USB drive play? I used a card reader with a memory card, and it worked before, but now it always switches back to the radio interface.