You won't be changing the file. You'll still have the embedded subs (which, apparently, your television can't read), but you'll also create an external subtitle file. You'll just be using the MKVExtract portion of MKVToolNix. Also make sure the subs are in a format your television supports. Quote.
2. Start a movie on LG TV (with transcoding): no subtitles 3. After ~1 min playtime switched to direct play: still no subtitles 4. Starting the same movie on my PC (Google Chrome): subtitles working perfectly (FYI: Playing the movie on PC caused a remux because of the audio codec, so I attached the remux log too).
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