iFlash SD Card problem. iPod will not recognize the drive.

Hi, I recently bought an iFlash solo adapter for my iPod, and when I originally bought it, it worked fine. I'm using a SanDisk 64GB SD card. I have been having problems with it though since my last iPod died, I have had it in both a 6th gen as well as a 5th gen. but now no matter what I plug it into I will either get the red X or the sad iPod. I have tried formatting the SD card, I tried other devices, I've tried just about everything. If anyone has any ideas on why it won't work now, I would greatly appreciate it. Thanks!