OpenCV便宜的立体相机无法一次加载两个流

I have purchased an ELP-1MP2CAM001 which shows up as two webcam devices on Windows. If I open the Windwos default "Camera" app and Skype I can display the feeds from both the left and right camera at the same time. I don't think therefore it is a USB Bandwidth issue with two cameras coming into the same port which shows