Content translation allows users to adjust the categories for the translated article. Users can add their own categories, but a regression is causing the user provided categories to be ignored when publishing. This was reported in this comment
In order to prevent future regressions, it would be great to apply some automatic testing.
Note: This task is about an issue that exists only in development (and maybe testing) environments but it doesn’t affect production websites. The issue is that when translating an article, user-defined categories are not saved properly, they are totally ignored.