not scrolling

# .py

class Multicopter(GridLayout):

    def __init__(self, **kwargs):
        super(Multicopter, self).__init__(**kwargs)

class multicopterApp(App):

    def build(self):

        h = 700
        w = 1300
        Config.set('kivy', 'show_fps', 1)
        Config.set('kivy', 'desktop', 1)

        Config.set('graphics', 'position', 'custom')
        Config.set('graphics', 'height', h)
        Config.set('graphics', 'width', w)
        Config.set('graphics', 'top', 15)
        Config.set('graphics', 'left', 4)
        Config.set('graphics', 'multisamples', 0)

    root = Multicopter()
        return root

# .kv
<Multicopter>:
    cols: 2
    GridLayout:
        cols:1

        Button:
            text: "Hide all"
    # ...
    Splitter:

        max_size: self.parent.width - 50
        size: 1100, 400
        size_hint: None,1

        GridLayout:
            cols: 2
            padding: 5
            ScrollView:
                id: scroll_steps
                StackLayout:
                    id: layout_steps
                    height: self.minimum_height
                    orientation: 'lr-tb'