mergerfs becomes the user making the request and because /media/usb/ is not permissioned to allow 1000:1000 to read the directory it won't show up to plex.
In the very least any directory being created automatically for mounting filesystems should be readable and executable by "other" and permissions be allowed to be set from the file browser. I'd suggest maybe even setting newly formatted filesystem root dirs to 1777.
Using Plex from app store with user and group set to 1000:1000.
mergerfs becomes the user making the request and because /media/usb/ is not permissioned to allow 1000:1000 to read the directory it won't show up to plex.
In the very least any directory being created automatically for mounting filesystems should be readable and executable by "other" and permissions be allowed to be set from the file browser. I'd suggest maybe even setting newly formatted filesystem root dirs to 1777.