Translating closed captions in Rise with localization

I am experimenting in Rise with the new localization feature, but I'm struggling to have the closed captions in the video automatically translated. 

The course is translated into 4 different languages. I've added a new chapter to each translated course, included a video, and added the closed captions (as a vtt file). However, after re-translating the course, the closed captions remain in the same, original language.

This article mentions adding closed captions to the video before translating the course. Is it also possible to apply localization to closed captions after they have been added to an already translated course?

Thanks,

Merel