This is an update to this issue: http://feedback.coronalabs.com/forums/188732-corona-sdk-feature-requests-feedback/suggestions/5416670-allow-external-music-audio-to-keep-playing-in-back
It seems like It got fixed back in 2014, but I’ve since seen this occur again. If I launch the app with music playing the music pauses. I’ve not been able to pinpoint when this got introduced because my app won’t build on too old versions of corona. Have anybody else seen this issue again?