§k is a valid formatting code that represents "obfuscated", where the text following this code will appear randomly changing like "magic". This works normally on English Minecraft, but as soon as "Force Unicode Font" is turned ON on the language menu, the text simply cannot show the randomly changing effect.

There are mainly 3 ways to reproduce the problem:

1. Open a book and quill, copy and paste some text that begins with "§k". You'll first see the magical effect. Attempt to turn on "Force Unicode Font" (or switch to a language that uses Unicode font), and then the effect is lost. The text will only appear static and as same as what you've entered.
2. Call any commands that supports "json". e.g. /tellraw. Adopt the "Obfuscated" style by something like /tellraw @a {"text":"","extra":[{"text":"MAGIC!","obfuscated":"true"}]}. You'll first see the magical effect on the chat window. Attempt to turn on "Force Unicode Font" (or switch to a language that uses Unicode font), and then the effect is lost. The text will only appear static and as same as what you've entered.
3. Change any text to display outside of Minecraft. e.g. changing the server name in server.properties, such that the text should contain the "obfuscated" effect. You'll first see the magical effect. Attempt to turn on "Force Unicode Font", and then the effect is lost. The text will only appear static and as same as what you've entered.

So the general idea is that "obfuscated" effect cannot be shown properly under Unicode Font mode, regardless of the actual language you're using in-game.