I have an LG G4 with an installed SD card. I have copied music to the SD card from my computer, but I cannot find an app that will recognize/find the music files on the SD card. If I go to the files from File Manager, I can play them, but I want to use an app so that I can play the songs randomly. I've been able to do this on all of my phones in the past. Why can't I do it on the LG G4?