Langauge override with Powershell not Working

Hello! I am trying to make an automating script to configure a set of PC:s one of the settings im trying to automate is

override Language, both UI and Input but nothing happens when i enter the cmd-lets in PS i use:

Set-WinUILanguageOverride en-US but nothing happens, i don't get an error message in PS and the setting does not change

Exactly the same with Set-WinDefaultInputMethodOverride.

I read about a bug in 1803 but i dont think it's related,

tried using a PA account and running PS as Admin

Please help