WPF Menu displays to the left of the window

Question

I have a simple Menu in a DockPanel. Here is the XAML:

Answer 1

It appears that you have a tablet input device. Follow the instructions in this link to change the handedness in your Tablet PC Settings:

• menus appear to the left of my cursor

Answer 2

A fix that worked for me was:

        var ifLeft = SystemParameters.MenuDropAlignment;
        if (ifLeft)
        {
            // change to false
            var t = typeof(SystemParameters);
            var field = t.GetField("_menuDropAlignment", BindingFlags.NonPublic | BindingFlags.Static);
            field.SetValue(null, false);
            ifLeft = SystemParameters.MenuDropAlignment;
        }

Credit: https://www.telerik.com/forums/popup-is-opening-to-outside-window-in-splitbutton