Hi Jay this is off thread but try your V/R to select a song title from an SD file. Don't use it for media in my vehicle anymore but interested to see if the 15 recovers the rest of your music when you reselect manually after using V/R. Sorry in advance if it stuffs UP! I do know the fix if it fails to recover your SD music files.
Unfortunately I don't have a SD Card to my vehicle, I only utilise the USB port.
MY15 Jeep Grand Cherokee Limited CRD
Luxury Group II
Thanks Jay for your time, from memory I think it used to stuff up the USB files also when you use V/R. If you are game to give it a go. Just back up your USB but you can delete and reload the file that it corrupts if it goes wrong. Cheers.