If you need to fix-match it anyway… have you considered simply searching by the IMDb / TMDb IDs respectively (Plex Movie → IMDb ID, The Movie Database → TMDb ID)
Edit:
Matching the movie using the Plex Movie agent worked right away for me (automatic + manual matching):
Movies
&Me (2013)
&Me (2013).mkv
(leaving out the leading & resulted in a bad match though)