.net core Getting null User Name from ManagementObjectSearcher("SELECT UserName FROM Win32_ComputerSystem")

Question

I am stucked trying to get username from using the following post's code

ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT UserName FROM Win32_ComputerSystem");
ManagementObjectCollection collection = searcher.Get();
string username = (string) collection.Cast<ManagementBaseObject>().First()["UserName"];

This works when I debug locally on my PC Windows 10 and Visual Studio. Also Environment.Username brings back my login UserName.

However, when I deployed to Windows Server, I get the service account for Environment.Username and null for the WMI call.

I also tried another post's approach

foreach (System.Management.ManagementObject Process in Processes.Get())
{
    if (Process["ExecutablePath"] != null && 
        System.IO.Path.GetFileName(Process["ExecutablePath"].ToString()).ToLower() == "explorer.exe" )
    {
        string[] OwnerInfo = new string[2];
        Process.InvokeMethod("GetOwner", (object[])OwnerInfo);

        Console.WriteLine(string.Format("Windows Logged-in Interactive UserName={0}", OwnerInfo[0]));

        break;
    }
}

On my .net core, I have to use allowAnonymous and WindowsAuthentication. I am reading a few posts that said there is a way to get the logged in user name and not the service account.

So far, no success.

Any help is appreciated. Thanks