I have an MP4 that I had originally ripped form its DVD using Handbrake, which I included an SRT file to encode the resulting MP4 with subtitles. After doing this, I would play the movie in VLC and the subtitles track was available in Sub Track under the Subtitles menu. I can still get the subtitles by manually selecting the SRT file the movie was originally encoded with, but this defeats the purpose of encoding it in the first place. I reencoded the movie to another MP4 file and included the subtitles track using VLC's convert/save function. However, when I play the new MP4 there is no subtitle track in Sub Track either.
How does a movie that originally had this suddenly lose it?