Plex server does not see files and subfolders in video folder on Synology

To augment here:

Synology reserves all rights and controls access to the default video share

It is for this reason we URGE everyone to make their own share(s) independent of the default/pre-created shares. We also urge to NOT place media in the Plex share (that’s for internal Plex use only to store your metadata)

This FAQ walks through setup of Plex on a Synology.