Latitude 7480 touchpad sometimes lost the control

The latitude 7480 touchpad sometimes loses control and looks like being hacked and controlled from outside, even though I had done the factory reset. I don't know how to describe it; please see my illustrated video for more clarity. Could anyone please help?

https://photos.google.com/u/3/photo/AF1QipNq6iLu3omRBXFp0eWDzA-p5Ns6m6o0ksgLbi45