Thank you, but I managed to figure it out. I had been translating the language files in this folder:
themes\neighborhood\includes\swift-framework\meta-box\lang
And nothing worked. But then I found another language folder, and translated the files:
themes\neighborhood\language
Now everything is fine.
But what does the language files in the “meta-box” folder do? They seem to have a lot of the same entries, including “Add to shopping bag”, which got me confused…