ok not sure about moving files but i had this same issue, but i couldn’t see my usb drive in my linux os either, so here is how i fixed it, and can now use it in win7 or Kubuntu
First I downloaded a free partitioning software called EASEUS it could see the usb stick and i told it to wipe all data and partition to a FAT32 after that windows was able to see it as an empty drive and I was able to make a Kubuntu startup disk, which is what i got it for. By the way the process too a long time to wipe and partition.
Hope that helps anyone else who might have this issue
