DNG files not appearing in Plex

It appears that, at some point, Plex quit cataloging DNG files. My camera is always set to save photos in RAW(DNG) and .JPG format. I copy these folders to my hard drive, and then tell Plex to scan library files. It picks up the .jpgs, but not the .dng files. Looking back through older libraries where I used to see .dng files alongside the .jpgs, the .dngs are all gone.

I’m not aware of any setting that would account for this. Any idea what’s going on?

Linux Mint 17.1
PMS Version 1.7.1.3856
Plex Web Version 3.7.0

@keithah Is anyone aware of this?

Never mind, if you ever paid attention in the first place. Some time in the distant, memory-stricken past, I added .dng files to a .plexignore file. Mystery solved.