Not all Files Recognized / added after data relocation

I’m not familiar with that brand, but most NAS operating systems are somewhat Linux/Unix based. I just presumed yours was similar. If you don’t have a touch cmd, then try doing the Plex dance with the affected media file. Say it’s a movie, move it out of your Movie library, scan your library, see if the movie disappears. Once it does, move the movie back under the Movie library, scan if you don’t have auto scans enabled.