[solbero]

All the privileges seems to be all right on the drives mounted by usbmount. You should be able to open the folder /media/usb, which is your Toshiba drive, with the Kodi user. Obviously when mounted under the het user in the folder /media/het they are only accessible by that user.

What is happening here? Well, if I remember my linux correctly, both /media/het/TOSH-2TB and /media/usb point to the same location in /dev/. Probably /dev/sdc since it seems like you have two internal hard drives which would be /dev/sda and /dev/sdb. When a drive is mounted in /media/ with certain privileges at the mount point, those privileges are carried down to the drive when accessed from that mount point. That is why /media/usb and /media/het/TOSH-2TB should show the same content, but have different user privileges for access.