Suddenly, the iOS and the Apple TV app will no longer display the subtitles embedded in my m4vs. The apps correctly list in the pre-play screens that the subtitles are present, but they are not shown when playing back the movie. Also, the subtitles displays nicely using Plex Web on my iPhone.
This has worked well before (maybe a regression in the apps or a recent PMS version (likely the 1.4 series) - I am now on the newest PlexPass one). Being a Plex veteran, I have seen this break from time to time - each time, it is very annoying so please fix asap!