General :: Files Not Visible On External MicroSDXC Card

I have a Samsung Galaxy Note 2 (US - Sprint) and received the following external memory card yesterday: Amazon.com: Kingston Digital 64GB MicroSDXC Class 10 Flash Card (SDCX10/64GB): Computers & Accessories

I was previously using an old 8GB class 6 miscroSDHC card with no problems. I removed that card form the phone, inserted the new card and formatted it (exFAT). The phone had no trouble seeing 59ishGB of the new card.

I removed the new card from my phone and inserted it into my laptop. The phone had created a folder called "LOST.DIR" but other than that the card was empty. I created a folder called "Music" and proceeded to move just under 8GB of music folders/files to it overnight.

This morning I removed the card from my laptop and inserted it into my phone. I opened the "My Files" app and when I opened the "extSdCard" folder there was nothing there. I removed the card and reinserted it in my laptop and the "lost" and "music" files were both available. I removed the card once again and reinserted into my phone and after about 15 seconds or so the phone rebooted. Once the phone powered on it rebooted again. Once it powered on again it rebooted once more and this time it powered into safe mode. Once in safe mode, I checked for the card and low and behold I could see both folders and I was able to play mp3 files from the music folder.

The phone shows 51.06GB of 59.01GB free on the external card, whether in safe or regular mode. Every time I removed the card from the phone or laptop, I unmounted it first. I've read that Android sometimes doesn't play well with Windows folders, but I've never had a trouble with this on any other Android handset.