I plug in my midi and (normally) I can play the midi while my song is paused and hear the notes as I physically play them. I would also be able to hit a note in the midi editor and hear that too. Today I plugged in the midi and saw the midi icon (shown in the picture) turn blue when I pressed a key, however, I did not hear anything. I could play my song and hear that just fine, but not the midi (when my song was paused or when it was playing). Also, I was unable to hear the keys I pressed in the midi editor. Is there something in the settings that I need to change?