Some characters flicker oddly when obfuscated

The bug

I performed a /tellraw command with the obfuscated string, and I noticed that by typing certain characters like: @, l, L get obfuscated with only: ~, µ.

I do know about the font change, but it just looks a bit weird as it also flickers a bit too. This is also the case with /title command that uses the "obfuscated" string.

How to reproduce

1. Run:

   /tellraw @a ["",{"text":"@@@@@lllll@@@@@","color":"green","obfuscated":true}]