Webview 5.11 presenting blank window from local intranet site, C# WPF

Question

I'm trying to set a very simple WPF application that will only pull a local HTML page that is a live and functioning as expected, hosted in our work place. we have no internet connection within the LAN.

I added succesfully WebView 5.11 (also tried 6.0 with same results) and added the following code:

<WPF:WebView Source="https://localSiteAddress" x:Name="wv" IsPrivateNetworkClientServerCapabilityEnabled="true"/>

this results in a blank page.

I was triyng to do the same through the code CS file and I added the following code:

private void Grid_Loaded(object sender, RoutedEventArgs e)
{
     var wv = new WebView();
     wv.IsPrivateNetworkClientServerCapabilityEnabled = true;
     wv.Source = new Uri("https://localSiteAddress");
     grid.Children.Add(wv);
     wv.BringIntoView();
}

same behavior

I was trying to access multiple local intranet websites with the same result. Note: when i use an external PC with Internet connection i nanage to access websites

Anyone pelase help :) any suggestion will be so welcome ... I wasted 48 hours already:)

Thanks