Then you are accessing a Plex server that is running directly on a NAS device.
It doesn’t matter from where you are loading the web app into your web browser. You were loading it from the plex server on your PC.
Looking at your account, I can see running Plex servers on your PC, and both NAS devices.
Plex apps provide you access to content on all your servers at the same time.
And this particular item is located on one of the NAS devices and was indexed by the Plex server running directly on them.
Check the library properties and see at which folder the library has been pointed at.
It is most likely that you have given it either a wrong folder or one that is too high up in the hierarchy.
https://support.plex.tv/articles/200289266-editing-libraries/
