I think the Photos folder is something that Synology creates for its own use and Plex struggles with the permissions on this.
Try creating a different folder for you photos and make sure the Plex user has access to the new folder.
See my reply here:
I think the Photos folder is something that Synology creates for its own use and Plex struggles with the permissions on this.
Try creating a different folder for you photos and make sure the Plex user has access to the new folder.
See my reply here: