Problem:
We have a custom content type "Event". This custom type has two categories: "Live event" and "Webinar". I need to translate these terms but there is no way to do this via the "Event Categories" page in the backend.
Solution:
The issue here is that "Events" categories don't have translation activated (wp-admin/edit-tags.php?taxonomy=event-category&post_type=event). The language options are missing on the CPT GUI.