Uploading file to onprem Sharepoint hangs in WPF .net 6 application

'ello

The following code just hangs on the ExecuteQuery() - it does not thows an error, it just never returns.
The exact same code works fine in a WinForms .net 6 application

` public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);

		var filePath = @"C:\temp\raw Material Receipts\RMR_20220224062549.pdf";
		var fs = new FileStream(filePath, FileMode.Open);

		var x1 = new AuthenticationManager();
		var ctx = x1.GetOnPremisesContext("https://docs.namibmills.com.na/");

		var lib = ctx.Web.Lists.GetByTitle("Raw Material Receipts");
		var newFileInfo = new FileCreationInformation
		{
			ContentStream = fs,
			Url = $"{Path.GetFileName(filePath)}",
			Overwrite = true
		};

		var file = lib.RootFolder.Files.Add(newFileInfo);
		ctx.Load(file);
		ctx.ExecuteQuery();
	}
}`