Cannot initialize ChromiumWebBrowser inside a JSB-bounded class

I have followed this steps to setup JSB. In my bounded-class, I need to return the source of an API request (I cannot, therefore, use GetPageSourceAsync because no JS context is ever created). So, I use the trick of copying and immediately pasting the page content to a string variable (see result). This code is not working, I get the following exception:

The ChromiumWebBrowser instance creates the underlying Chromium Embedded Framework (CEF) browser instance in an async fashion. The undelying CefBrowser instance is not yet initialized. Use the IsBrowserInitializedChanged event and check the IsBrowserInitialized property to determine when the browser has been initialized.  

which is happening on bro.SelectAll();:

public class boundClass
{
        ChromiumWebBrowser bro;

        public boundClass()
        {
            bro = new ChromiumWebBrowser("https://google.com");
        }

        public string getAuthSource(string url)
        {
            string source = String.Empty;

            bro.Load(url);

            while (bro.IsLoading)
            {

            }

            bro.SelectAll();
            bro.Copy();
            string result = Clipboard.GetText();
            Clipboard.Clear();

            return result;
        }

    }

What's the problem? The ChromiumWebBrowser seems well-initialized to me...