I have been saying this forever, i have no clue why all subtitles are not available. When I was in italy all of my favorite shows had italian subtitles, now im back in the US, they disappeared.
Change your netflix app language to your target language and you magically get more subtitle options, if available. In US Netflix, when I set my language to english, I see english, spanish, and maybe french or italian for some shows. When I set my language to Korean, I see English, Korean, Japanese, and Chinese (trad and simplified) when they are available for that show.
Why they base it on your display language and don't just have a setting that is "show me X, Y, and Z language subtitles if available", I don't know.
Why they base it on your display language and don't just have a setting that is "show me X, Y, and Z language subtitles if available", I don't know.