There are a few things you can try in order to get external subtitles to display on your Smart TV:
Check subtitle file format:
Ensure the external subtitle files are in a compatible format like .srt.Check whether subtitles are turned on:
Check the subtitles settings on the Smart TV.Check video file format:
Ensure the video file format is compatible with the Smart TV.Configure external subtitle settings:
Configure external subtitle setting on the Smart TV.