@Rudy_Ooms_MVP as far as I see in Intune the application is configured correctly. This is the detection script:

try{
$iCountry = (Get-ItemProperty 'HKCU:\Control Panel\International' -Name iCountry -ErrorAction Stop).iCountry
$Locale = (Get-ItemProperty 'HKCU:\Control Panel\International' -Name Locale -ErrorAction Stop).Locale
$iCurrDigits = (Get-ItemProperty 'HKCU:\Control Panel\International' -Name iCurrDigits -ErrorAction Stop).iCurrDigits
$iCurrency = (Get-ItemProperty 'HKCU:\Control Panel\International' -Name iCurrency -ErrorAction Stop).iCurrency
$iLZero = (Get-ItemProperty 'HKCU:\Control Panel\International' -Name iLZero -ErrorAction Stop).iLZero
if($iCountry -eq 972 -and `
$Locale -eq '0000040D' -and `
$iCurrDigits -eq 2 -and `
$iCurrency -eq 2 -and `
$iLZero -eq 1){
Write-Output "International configurations were set correctly"
exit 0
}
}catch{
$ErrorMessage = $_.Exception.Message
Write-Error $ErrorMessage
exit 1
}

 

If this detection script is wrong I'll be happy to know what to change. As I said, this works manually in OOBE.