Note 3 Automatically deletes all .mp3 and .ogg files from MicroSD?!?

I've given my son my Note3 to play with but every time I copy music to the microSD the damned phone goes and deletes all the files. It leaves the folders but deletes all the .mp3 and .ogg files!

what the hell could be doing that?

Its unrooted and running stock N9005VJUGBPB1_N9005ZTMGBOK3_N9005VJUGBOL1

from xda-developers http://ift.tt/1X3xr0H
via IFTTT