Not sure if this is the right place to go with this question: However, before I file an issue with this, I'm wondering if it is something I'm missing or doing wrong.
The problem. Given a language (lets say Spanish), I have defined another custom language (Spanish, Mexico) From /admin/config/regional/language, I nest Spanish, Mexico with Spanish as a fallback.
Next, I define a translation for Spanish, Mexico.
Expected Result: a translation for that term unique to Spanish, Mexico, and a separate translation for Spanish.
I have created a fresh install of Drupal 8.9.9 and have only installed https://www.drupal.org/project/language_hierarchy (V.2.0.0-rc2). Also tried 2.x-dev (same error)
Actual Result: the Spanish, Mexico translation overwrites the Spanish.