Right after i bought the Surface 3 i bought a 64GB micro sd card to go with it. It was working perfectly with no problems for a few months. Then about a month ago it will not save any new items, exp. docs, pics, music etc. It also will not let me delete these items. Now when i first add a file, it will show up. The same goes for when i delete a file, it will show it gone. When i restart the surface it is like nothing happened. It is like it is locked the way it was a few months ago. Any help on this ?