Android Question WV_OverrideURL event not being triggered for a Data:Base64 link

Sub Globals

   Private WebView1 As WebView
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("1")
   Dim dl As JavaObject
   dl.InitializeNewInstance(Application.PackageName & ".main$MyDownloadListener", Null)
   dl.RunMethod("set", Array(WebView1))
   WebView1.LoadUrl("https://flaviocopes.com/data-urls/")
End Sub

Sub DownloadListener_Event (MethodName As String, Args() As Object) As Object
   Log(MethodName)
   Return Null
End Sub

Sub WebView1_OverrideUrl (Url As String) As Boolean
   Log(Url)
   Return False
End Sub

Sub WebView1_PageFinished (Url As String)
   Log("page: " & Url)
End Sub

#if Java
public static class MyDownloadListener implements android.webkit.DownloadListener {
public void set(android.webkit.WebView wv) {
   wv.setDownloadListener(this);
}
 public void onDownloadStart(String url, String userAgent,
                                String contentDisposition, String mimeType,
                                long contentLength)
       {
       BA.Log("Test");
       }
       }
#End If

public void onDownloadStart(String url, String userAgent,
                                String contentDisposition, String mimetype,
                                long contentLength)
       {
       processBA.raiseEventFromUI(this, "ondownloadstart", url, userAgent, contentDisposition, mimetype, contentLength);
       }
       }

Sub onDownloadStart (url As String, userAgent As String, contentDisposition As String, mimeType As String, contentLength As Long)
    Log("url: " & url)
    Log("userAgent: " & userAgent)
    Log("contentDisposition: " & contentDisposition)
    Log("mimeType: " & mimeType)
    Log("contentLength: " & contentLength)
End Sub