So I got the drive to work, but only if it's plugged in to the usb port when the cdj is off. If it's plugged in while the cdj is off, and I power the cdj up, the usb port on the cdj will start flashing and the GTX 3.1 usb drive lights up, too. After that it seems to work fine. All my playlists are there, settings load on menu push, and songs play. Then, if I unplug it and try to plug it back in, nothing. Like nothing is plugged in. The usb port jb the cdj doesn't light up, the GTX usb doesn't light up, literally nothing happens. No error code either, like there's nothing plugged in.
I have the latest 1.84 cdj2000nxs2 firmware, rekordbox is the latest version 5.5.0, and again the GTX 3.1 usb is formatted (single, MBR primary partition) FAT32 and works fine in rekordbox, syncs up just fine, all my songs synced.