It sounds like the audio subscription isn't active.  You will always get the one demo channel with any of our weather units.  To get Sirius/XM audio it must be part of your subscription and properly activated. Once activated, you should have no problem changing channels.  If you have audio as part of your subscription, I would recommend you refresh/re-activate the unit with Sirius.  Wait 20 mins after refreshing, then fully power cycle the receiver.  Hopefully then the audio will function for you.