Naming glitch?

[JuiceWSA]

The LMA Hack is needed:

Video File Naming

With LMA in priority, Embedded Titles within MP4/M4V files are preferred - even over a perfect file name. Local Media Assets should - AT ALL TIMES - remain enabled (unless specifically instructed to turn it off). Local Media Assets should be ‘Demoted’, to the bottom of the stack of active agents under ALL tabs in Shows and Movies, but should NOT be disabled. Local Media Assets is needed for many things - it doesn’t need to be given Tip-Top-Priority (as Plex has so hatefully placed it as it’s …

There is embedded metadata in your MP4/M4V file throwing Plex into a tailspin.
the LMA Hack tells Plex to stop looking in your files for embedded titles and to concentrate instead on your good file names.