1. Unmount USB partitions sudo umount /dev/sda*
  2. Wipe boot/ISO signatures sudo wipefs -a /dev/sda
  3. Create fresh partition table sudo parted /dev/sda --script mklabel msdos
  4. Create 1 full size partition sudo parted /dev/sda --script mkpart primary fat32 1MiB 100%
  5. Format as FAT32 sudo mkfs.vfat -F 32 /dev/sda1
  6. Verify its clean lsblk -f
  7. Reconnect USB udisksctl mount -b /dev/sda1

Optional:

  • Give it a name: sudo fatlabel /dev/sda1 USBDRIVE