When I go in the music app it works fine, then I lock it it still works. But when I press the lock button to unlock it the noise suddenly stops working. When I do unlock it the song is still playing but I can't hear anything, even if the Media Noise is all the way up. I have to pause the song and exit the music app. Then I have to change the ringtone volume so that the noise comes back to the headphones. Can someone help me, please.