Rekordbox 5.0.2 USB detection issues

Im using Rekordbox 5.0.2, in HighSierra for Mac. I have a SanDisk extreme go 64gb USB drive, which isn't being detected under the devices tab, whilst being recognised by Finder on the OS. The drive is formatted as FAT32, and was previously working in Rekordbox 4 on HighSierra.

I have tried booting in safe mode and reformatting the usb with no success.