Android Studio Translations Editor doesn't add new locales

Heyo. I want to utilize translations in my demo app I'm building for my semester project (deadline is tomorrow, btw, I'm in CET timezone, so I have to finish it before going to bed tonight, since I don't remember if the deadline is tomorrow midnight or earlier, and I'm at work during the day, I return back at 8:00pm CET). The only issue is that when I add a locale, it doesn't show up, and refreshing the page does nothing. It adds a new directory in the project tree (values-cs), but it's empty and the locale doesn't show up in the translations in any way, and I can't add the translations. It's not really that much important, but I'd like to introduce the ability to choose a language. For now, I'll just build it in English, but please, help me out.