SOLVED: Completed / unseen films keep getting shown in "Continue Watching"

[noncrab]

This only seems to happen with a few recently added films. 
What I'll observe is that:

• Films A and B (not started, and completed respectively) are showing up under Continue Watching on the home page.
  
• I'll toggle the "mark played/watched" button twice (to reset the status)
  
• Reload the page. The film no longer shows up.
  
• <time passes>
  
• Without any other changes, the film is now in Continue Watching again. (Sometimes the playback position gets reset to ~halfway through the film)
  

I've poked around a bit, enabled debug logging, and as best I can tell it has something to do with a batch job, in the sense that:

• I've noticed that the resume status is contained in the .nfo XML
  
• Comparing the modification time of the .nfo files seems to point to a time when Jellyfin was running a batch job, seemingly associated with MediaBrowser.Providers.Manager.ProviderManager.
  
• The mtime of the file 
  

I'm not quite sure how to read these logs, but that's my best guess. (Otherwise I'm a relatively proficient software engineer, but have no clue about C#, or Jellyfin)

It's going to be quite time consuming to redact the logs, so if there are specific lines I should pick out, please let me know. I currently have TmdbMovieProvider and OmdbItemProvider enabled for this Library.

Can anyone help please?