Step to reproduce :
1 run this code
    @Override
    public void start(Stage stage) throws Exception {
        VBox root = new VBox();
        root.getChildren().addAll(
                MenuBarBuilder.create().menus(
                MenuBuilder.create().text("File").items(MenuItemBuilder.create().text("New").build()).build(),
                MenuBuilder.create().text("Help").items(MenuItemBuilder.create().text("About").build()).build()
             ).build()
          , new Button("Button"));
        Scene scene = new Scene(root, 500, 500);
        stage.setScene(scene);
        stage.show();
        stage.setTitle(VersionInfo.getRuntimeVersion());
    }
2 button have focus after start application.
3 Press TAB - focus of the mouse will move on the menu (you can check this by pressing the SPACE - will open popup window), but it will not allocated as the active