this has been a long standing (like 4 months or so) bug for me, it also happens with the File, edit, window, help menus INSIDE the editor while running. this really limits what you can do. in the launcher you cant manage any of the user files.
right clicking the launchers icon in the system tray is also always bugged out when this happens and the flyout there actually shows up but in the center of the screen on the wrong monitor.
what ever non standard way they are using right click in the launcher and inside the engine doesnt mesh with Windows 10.