Plex Media Server version? 1.29.2, 1.30.x, etc.
DSM 6 or 7?
Movies and Shows on Plex is the free, ad supported streaming service. It has nothing to do with your files on your server.
This usually comes down to either naming & organization or file permissions.
Naming & Organization
Please show how you have the files named and organized - directory listing, screenshot, etc. Include the full path to the files and the file extension.
Make sure you follow Plex naming and organization requirements.
Plex Documentation → Your Media
→ Naming & Organizing Your TV Show Files
→ Naming & Organizing Your Movie Files
File Permissions
Verify that Plex Media Server has at least read-only permissions to the files.
DSM 6: FAQ 24: Restoring Share Permissions to Default Settings
DSM 7: FAQ 30 - DSM 7 - Give PlexMediaServer access to your media
