Hi can anyone help me pleaseI am a Mac user I have never had a problem with my meta data before until the wonderful app changeover

I have upgraded my whole system to be gen 2 when my Sonos is playing the ID tags and artwork is not coming up properly now but some of it is and all I have done is changed from GEN one to GEN two 

When I look up in iTunes they are tagged and artwork is there so why when converting it to Sonos does this all change and go wrong?

If someone can explain this step-by-step would be wonderful