Unable to change Illustrator CC2020 app language from English to Norwegian

I'm attempting to switch my Illustrator CC 2020 from English (International) to Norwegian. For recording some tutorials. Although cumbersome, it works fine for all other apps, but not for Illustrator.

1. I have created a new Windows 10 user account (just in case).

2. I have changed the Windows language to Norwegian (this seems to affect the language of the CC desktop app only).

3. I have uninstalled Illustrator, removing all preferences (both normally, and with CC cleaner).

4. I have uninstalled the CC desktop app (both normally, and with CC cleaner).

5. I have reinstalled the CC desktop app.

6. I have set the default application language (in the CC desktop app) to Norwegian.

7. I have reinstalled Illustrator.

I have been reinstalling Illustrator like 10 times now. It ends up as English every time no matter what I do. At some point I deleted some OOBE-folder as well (forcing it to be recreated). There must still be some obscure hidden file/setting somewhere locking the language to English (but where?!).

Any idea how to fix this?

The one thing I have not attempted yet is to remove every single adobe-related application from my system (there is a lot) and then manually doing search-and-delete for every file and registry entry I can find related to adobe. I'd rather not. I have also not attempted to reinstall Windows. Again, I'd rather not. Changing app language should be as simple as picking the language in a drop-down in preferences, but as it stands it is somehow easier to change the language of my entire operating system than for CC apps. 😞

{Renamed by MOD}