Preset saving to thumb drive not working as intended

The 5 octaves worth of presets I access through my arturia keystep seem to be saved on the hypno itself, as I can overwrite/recall them without having a usb stick inserted. This is great but my hypno doesn’t save new new presets on any fat32 usb sticks I’ve added. After attempting to save a newly created patch as a preset onto a newly formatted drive, I move the drive to my desktop and see on my computer that the drive is blank, with no JSON files, folders, anything.

I’m hoping to hotswap drives.

are you on the latest firmware? are you able to use mp4s from the drive?