ChuckPa
4
When you mount USB drives (pretty much ANYTHING in /media)
-
Don’t let the automounter do it. Permissions look right but never work.
(Nautilus does what it wants and not what it’s told )
-
Make a mount point directory away from /media which is stable and username-idependent.
This How-To has been available for a while 
The TL;DR -
- You own the media and have full control.
- You grant ‘plex’ permission (RO or RW) as you deem appropriate
- Issues disappear