So… you have Red Notice as an example earlier of “not available” but you used Terminator for the movie path… so now we have to ask, is Terminator also showing “not available” in your Plex?
Try not to hurry through this, it’ll help avoid repeating things. 
The paths actually do match between library and the Terminator example so they should be fine as long as that folder is available.
Now. Did you add a drive from your computer to your NAS and then add that to Plex instead of copying your files to the NAS? That would explain things of you did… adding the folder of your laptop to Plex just links it, doesn’t copy or move it. Does that sound familiar?
It’s also possible if you recently upgraded your NAS that you haven’t updated the new permission settings. Have you recently updated to DSM7? You’ll want to make sure you set the correct permission otherwise Plex can’t see your media… follow these instructions.
Also, go to your account page on Plex and screenshot connected devices… it’s possible you have two servers setup. That could also explain some things.
