Could not resize application window in silk4j using size method

I try to resize an application window in my test script. I could manually resize it. But when I try following code in automation,  the window get focused and moved as expected, but does not get resized. It remains original size without throwing any exception

desktop.<Window> find("Window2").setActive();

desktop.<Window> find("Window2").move(new Point(755, 188));

desktop.<Window> find("Window2").size(827, 638);

Anyone has any idea?