Added second folder location to library but plex doesn't seem to be scanning it

[ChuckPa]

Which NAS ? Synology ?

If so, we have a Synology FAQ with info.

Synology FAQ - Questions, Answers, and How-To's

FAQ 19: Setting permissions to allow Plex access to media files Before beginning, it’s important to remember one key point; Plex doesn’t have any special privileges on Synology except for being able to access the Video Transcoding acceleration hardware. It cannot read any of your files unless you expressly grant permission. This is a fundamental principle of Linux (which Synology uses for DSM) Because of how Synology grants permission, access to files is broken into two different …

and

Synology FAQ - Questions, Answers, and How-To's

FAQ 29 - DSM 7 - Give PlexMediaServer access to your media When you migrate to DSM 7, are installing a server for the first time, or just adding a new shared folder / sub-folder for media , folks forget to read the popup at the end of every installation which tells them about how to set permissions. This FAQ shows in detail how to do what those instructions state. When might you need to perform these steps? When upgrading, changing permissions from Plex to PlexMediaServer is overlook…

Plex is not privileged on Synology. You need to give it permission to read those folders you want it to access.