Related tip if you won't/can't use this extension: Netflix shows normally have many more subtitles available than you get shown (and sometimes audio tracks). The selection you see depends on your interface language and locale. For example, I can't use Spanish subtitles for one show ( https://i.imgur.com/BBWuuPs.png ) until I change my interface language to Spanish ( https://i.imgur.com/bsyYJGR.png ).
I still can't get my head around how user hostile they made this. I mean, why? I understand showing the most likely languages on top, but why hide content that's available? I have bilingual kids (Dutch and Danish, living in NL) and the amount of setup we have to do each week to get and keep Danish audio for cartoons on Netflix is pretty nuts.
There are all kinds of permutations like that which can look like arbitrarily bad UI decisions if you don't know the greater context.