Robot mouseMove() not working with edge but working well with chrome and firefox

Question

I have to do cross browser testing where need to test a scenario in chrome,Firefox and edge.

Scenario is: I have to move the mouse to a web element and then move the element few pixel ahead and then release the element.I am using robot framework to do this.It's working well with chrome & Firefox But edge is unable to drag the element. I am unable to understand the issue.

Any help will be greatly appreciated.

The web element is attached [![enter image description here][1]

I am using : Selenium 2.53 Firefox version 46.0 Edge is installed in window10

My code is:

Robot robot = new Robot();
        robot.mouseMove(elemnt.getSize().getWidth()-4, elemnt.getSize().getHeight());

        robot.mousePress(InputEvent.BUTTON1_MASK);

        robot.mouseMove(elemnt.getSize().getWidth()+73, elemnt.getSize().getHeight()+20);

        robot.mouseRelease(InputEvent.BUTTON1_MASK);

        Thread.sleep(3000);