More than two webcam stream using the WPFMediaKit is not working

Question

I'm using WPFMediaKit for my project to display 4 webcams simultaneously on the same screen. I first, using the WPFMediaKit, tried running two webcams. It worked like a charm. But when I try to load more, only two of them works.

I'm in a fix. I purchased all four high end webcams (for a quiz show) and now I'm unable to load them at once.

Below is the code I used to do that. video1, video2, video3 and video4 is the VideoCaptureElement control found in the WPFMediaKit. When I use the function below, any two webcam video starts and gives live stream and any two remains blank.

I commented each line to test whether there is a problem with the webcam, but each and every webcam is running fine individually or in pairs. But all four together is not working.

Public Function LoadCamera()
            video1.Stretch = Stretch.Fill
            video1.VideoCaptureDevice = MultimediaUtil.VideoInputDevices(0)

            video2.Stretch = Stretch.Fill
            video2.VideoCaptureDevice = MultimediaUtil.VideoInputDevices(1)

            video3.Stretch = Stretch.Fill
            video3.VideoCaptureDevice = MultimediaUtil.VideoInputDevices(2)

            video4.Stretch = Stretch.Fill
            video4.VideoCaptureDevice = MultimediaUtil.VideoInputDevices(3)
End Function