How to switch MutableRuntimeReferenceImageLibrary?

Question

I know how to switch Reference Library, I am using the following function.

 public void switchImageLibrary(int curLibIndex)
    {
        trackImageManager.trackedImagesChanged -= OnTrackedImagesChanged;
        var newLib = curLibIndex == 0 ? "QR Library" : "Image Library";
        LogHandler.Instance.Log("Switching Library to :- " + newLib);
        trackImageManager.enabled = false;
        var lib = curLibIndex == 0 ? QRCodeImageLibrary : ImageAccessPointLibrary;
        trackImageManager.referenceLibrary = trackImageManager.CreateRuntimeLibrary(lib) as MutableRuntimeReferenceImageLibrary;
        trackImageManager.enabled = true;
        trackImageManager.trackedImagesChanged += OnTrackedImagesChanged;
        LogHandler.Instance.Log("Current Marker Count : " + trackImageManager.referenceLibrary.count);
        LogHandler.Instance.Log("Current Library name " + trackImageManager.referenceLibrary.ToString());

        for (int i = 0; i < trackImageManager.referenceLibrary.count; i++) {

            LogHandler.Instance.Log("Reference Added In Library : " + trackImageManager.referenceLibrary[i].name);
        }
    }

I can see after Job Complete and Marker added an event but after that nothing happen, Marker Tracking event was not updated !!