Unable to Add/Scan Library with new install

Thank you. Now I understand.

You’re using the automounter. ( /media/Your_username/<SOMETHING>)

Gnome totally hoses this up. No matter what you do, the automouter will mount it such that ONLY YOU can see it. User plex won’t .

To resolve this, make a manual mount point somewhere and make the entries in /etc/fstab

This contains everything:

What you should look at is probably: