I think I have this same issue. What really happens is that anything that would be controlled by 'media volume' no longer comes out the speaker. Headphones and Bluetooth do work. Searches on the net revealed a lot of talk about stuck headphone jacks and things but I never had this problem before... I can always reproduce it by running pandora for a while then stopping it. After that, no more sound from anything managed by 'media volume' until I reboot.
I'm having the exact same issue. Very annoying. Reboot seems only fix