Plex: unmatches movies randomly

Have you checked the Plex knowledge base and searched on the sub and Google:

Server version: Version 1.5.5.3634

OS: MacOS 10.12.4

Clients, w/ versions, if applicable: tested on Web (Plex.tv and by local IP) and with Plex for iOS

What you did? logged into plex and looked at movies

What happened? some (132 that i saw, maybe more) of the 1400+ movies were no longer matched to a movie. The video was there and you could play it. but all movie information was missing

What you expected? Movie information to be there

Link to logs (optional but recommended):

Workaround: Update library and it will rematch the movies, but issue has occurred twice this week.