Load iframe in CefSharp winform

Question

In my winform app I load a webpage in a cefsharp browser. In the webpage there is an iframe which loads another webpage.

In Chrome the iframe is loaded. In the app the iframe keeps blank.

I can't seem to find the solution.

I 've added a handler:

    browser.RequestHandler = New checkFrame()

    Public Class checkFrame
    Implements IRequestHandler

    Public Sub OnPluginCrashed(browserControl As IWebBrowser, browser As IBrowser, pluginPath As String) Implements IRequestHandler.OnPluginCrashed
    End Sub

    Public Sub OnRenderProcessTerminated(browserControl As IWebBrowser, browser As IBrowser, status As CefTerminationStatus) Implements IRequestHandler.OnRenderProcessTerminated
    End Sub

    Public Sub OnRenderViewReady(browserControl As IWebBrowser, browser As IBrowser) Implements IRequestHandler.OnRenderViewReady
    End Sub

    Public Sub OnResourceLoadComplete(browserControl As IWebBrowser, browser As IBrowser, frame As IFrame, request As IRequest, response As IResponse, status As UrlRequestStatus, receivedContentLength As Long) Implements IRequestHandler.OnResourceLoadComplete
    End Sub

    Public Sub OnResourceRedirect(browserControl As IWebBrowser, browser As IBrowser, frame As IFrame, request As IRequest, response As IResponse, ByRef newUrl As String) Implements IRequestHandler.OnResourceRedirect
    End Sub

    Public Function GetAuthCredentials(browserControl As IWebBrowser, browser As IBrowser, frame As IFrame, isProxy As Boolean, host As String, port As Integer, realm As String, scheme As String, callback As IAuthCallback) As Boolean Implements IRequestHandler.GetAuthCredentials
        callback.Dispose()
        Return False
    End Function

    Public Function GetResourceResponseFilter(browserControl As IWebBrowser, browser As IBrowser, frame As IFrame, request As IRequest, response As IResponse) As IResponseFilter Implements IRequestHandler.GetResourceResponseFilter
        Return Nothing
    End Function

    Public Function OnBeforeBrowse(browserControl As IWebBrowser, browser As IBrowser, frame As IFrame, request As IRequest, isRedirect As Boolean) As Boolean Implements IRequestHandler.OnBeforeBrowse
        Return False
    End Function

    Public Function OnBeforeResourceLoad(browserControl As IWebBrowser, browser As IBrowser, frame As IFrame, request As IRequest, callback As IRequestCallback) As CefReturnValue Implements IRequestHandler.OnBeforeResourceLoad
        'Console.Write(request.Url + Environment.NewLine)
        Return CefReturnValue.Continue
    End Function


End Class

Does any body knows what I need to change or add so the iframe gets loaded?

Thanks