New XMod owner - audio query

Hi, delighted with my new XMod...except...I've been using USB sticks for my music for ages in my previous cars - so all my collection is 'sticked up and ready'. However, I can't seem to get it to play a whole USB stick in random - only individual folders on the stick. Sincerely hoping this isn't just the way they are :(
Please can someone enlighten me?

New XMod owner - audio query