I don’t know whether this is an issue or by design.
When I drag the MenuBar from the toolbox and drop it on a windows, I expect it to Dock = Top as it happens with the ToolBar. In fact it isn’t docked at all.
On second thoughs, I wonder what’s the difference between MainMenu and MenuBar. Do we need a MainMenu?
The MainMenu doesn’t take space from the client area, participates in the Mdi merged menu system, doesn’t scroll with the client area content.
The MenuBar is simply a panel that contains a menu and can be used like any other control. The default is DockStyle.None because it can be used like a normal control anywhere in the container.