localized categories (categories.yml) from 3rd party repos not being used?

• Device OS and version: Android 11 (LOS)
• Device model/manufacturer: FP2
• F-Droid version (in the About screen): 1.16-alpha4, 1.16 (release), 1.16.1
• F-Droid privileged extension version (if installed): 0.2.13

What did you do? (clear steps if possible)

Switching to the categories tab and browsing categories

What did you expect to see?

All categories being localized properly

What did you see instead?

Only categories from f-droid.org being localized, custom ones from my repo not

Details

I've set up a config/de/categories.yml for my repo, starting with a copy of the file present in fdroiddata, and added the 4 categories specific with my repo to it. Looking into the clients category listing today I was surprised that, while the categories from f-droid.org showed up in German, the 4 categories of my repo did not:

Development:
  name: Entwicklung
Food:
  name: Ernährung
Games:
  name: Spiele

Is there an issue with "umlauts"? You see the relevant entry being present: name: Ernährung. But then, Automation (name: Automatisierung) isn't localized either. Investigating the index shows translations are there:

{
  "name": {
    "en-US": "Food",
    "de": "Ernährung"
  },
  "icon": {
    "en-US": {
      "name": "/icons/category_food.png",
      "sha256": "c3e5961a7339d62d49c72e68167627e6d3d06b1949ed54e53ef3f51bfe5613b8",
      "size": 12019
    }
  }
}

so it's not an issue on the end of fdroidserver but clearly the client. Further, the category has an icon defined – as the screenshot shows, that's not being used either. So the nearest assumption seems to be that category definitions from "custom repos" are ignored entirely (my category "Office" aka "Büro" also shows neither the German translation nor the image, the other custom categories have no icon set but the translation isn't used either).