Use DBRepair instead of the method in the Plex support article. See this post: Issue getting movies (tv shows are fine) to play on one TV and iphone - #2 by FordGuy61
Did you run any 1.41.7 releases?
You might have been bitten by the “database bloat” bug in some 1.41.7 releases.
After you run DBRepair, update to 1.41.8 (current public) if you’ve not already done so (to get off the problematic 1.41.7 releases).
The run the debloat routine.
See this post: Library.db size more than doubled in latest version - #410 by OttoKerner
Save the instructions as a .bat file (ex: deflate.bat), then run it from the command line like you did with DBRepair.
It should reduce your database file back to normal size.
