Kivy StackLayout not stacking floatLayouts

I am trying to stack several instances of a floatlayout, each with one button inside. I am using flaotlayout as I want to later adjust the relative position of the button horizontaly across the float layout while keeping the vertical position. When I use pos_hint to position the button in the float layout it works fine but I want to use pos = (x,y) and this results in all buttons overlappying so i can only see one... I would appreciate if anyone could tell me where I am going wrong!

i think the button is taking the pos of the window rather then the parent widget, is this the case??

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.stacklayout import StackLayout
from kivy.uix.button import Button



class BreaksPanel(FloatLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        self.size_hint = None, None
        self.width = 5000 
        self.height = 36 

        btn = Button(text='My Button', size_hint=(None, None), size=(75, 36), pos = (0,0) )  # pos_hint={"x":0, "y":0}) works fine but not pos = (0,0)
        self.add_widget(btn)



class BreaksWindow(StackLayout):

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

        self.orientation = "tb-lr" 
        for i in range(10):
            B = BreaksPanel()
            self.add_widget(B)



class Example(App):
    def build(self):
        layout = BreaksWindow()
        return layout


if __name__ == '__main__':
    Example().run()

The problem is your use of FloatLayout. In a FloatLayout, you can position its children anywhere and that is not restricted to the inside of the FloatLayout. So your Buttons are all positioned at the same pos (0,0). I think you are expecting the FloatLayout to act like a RelativeLayout, where pos of (0,0) is the lower right of the Layout. So a simple fix is to just make the BreaksPanel extend RelativeLayout:

class BreaksPanel(RelativeLayout):