Some Trailers don't work

Does anyone have any issues where some trailers (the extras you get with plex pass membership) do not work? They give a transcode failure error, even when the trailer works on the web app (on the hosting server machine). I get the error both on a Roku and the Android mobile app. The movies themselves play fine, so I’m not sure what the issue is.
Extra info:
Server is Linux Mint 18.2 (also desktop)
RJ-45 to router, and RJ-45 to Roku (wireless b/g/n connection for android and other devices)
Movies are in MKV containers

A specific movie/trailer I can point to as a problem is It (1990). The movie plays on all devices, but the trailer only plays on the server machine when I use the web app. Obviously, the trailer is part of the plex pass, so I don’t have it separately stored with the movie file as a local extra.

Some trailers work fine, as a plex pass extra, and all of my locally saved extras (featurettes, etc…) work fine as well. It’s only certain trailers for certain movies. I’ll try to update this question with additional ones as I identify them, until the issue is resolved.
Thanks everyone.

Update: problem also extends to:

  • White Men Can’t Jump (1992)
  • Space Jam (1996)
  • Wyatt Earp (1994)
  • Unforgiven (1992)

I can only guess that it’s some sort of bug in the way that Plex crawls the data. I figured out that if I put each movie file (and any extras) into it’s own folder (named for the movie with parenthetical year) it gets the trailers as part of the plex pass. It’s pretty cumbersome to make a folder, then move the movie and extras into it; so I made the following script, which I just keep in my movies library folder. Obviously, from the syntax, it only works for mkv files though.
#!/bin/bash
for x in ./.mkv; do
mkdir "${x%.
}" && mv “$x” “${x%.*}”
done
I made this a .sh file and set the file to be executable in Linux.