Steps to reproduce:
- Precondition: Open https://translatewiki.net/wiki/Special:Preferences to see the current user interface language in the user preferences. Make sure the user interface language is set to en.
- Open https://translatewiki.net/wiki/Special:Preferences?setlang=de to change the user interface language to de
- Current result: The user interface language is now de but the option field Sprache der Benutzeroberfläche shows: en - English
- Expected result: The new language should be selected in the option field.
The same problem also happens when changing via API setoption though the ULS.
A reload of the preferences with bypassing the cache (Ctrl + Alt + R) shows the correct setting.