I can give some tips.
- Never mix films with anything.
- Follow exactly the website articles on Your Media for naming and folder organization.
- A good Agent is
Settings > Agents > Movies > Plex MoviewherePlex Movieis checked and highest on the list. You can also haveLocal Media Assetschecked and first if you have external subtitles eventually. But for nowPlex Movieis better. - You will definitely want to do The Plex Dance as part of your re-organization.
Those tips will apply, even if you had no strange curl errors.
Have you tried cloning the Mini with SuperDuper and just wiping PMS, starting fresh with only 2 movies in a brand new folder and see what happens?