Why is my achievement in german?

Games Halo 5: Guardians
1

I was playing some custom games on Halo 5: Forge PC and I got the achievement for playing in a fireteam of 4, but it was in german…

2

are you german?

3

Mine was too… same achievement. It’s probably normal… I guess.

4

same here, very strange

5

Keine Anung. Tut mir leid