Kivy Does Not Update The Refreshed Data on The Screen [Video + Full Codes]

Kivy does not update the refreshed data on the screen.
If i restart the app, i can see the new data after calculation.
I want to see refreshed data on the screen after the calculation is done, without restarting the program again.

When i run the app, datas() function pulls the json file at the first time and also when i on the second calculation screen, before calculation, the Clock.schedule_once(self.datas) pulls the data again as well but sill i can’t see the refreshed names on the screen.

PY File:

    from kivy.app import App
    from kivy.uix.boxlayout import BoxLayout
    from kivy.uix.label import Label
    from kivy.metrics import dp
    from kivy.uix.behaviors import ButtonBehavior
    from kivy.clock import Clock, mainthread
    import json
    import threading
    
    
    class Test(BoxLayout):
    
        def __init__(self, **kwargs):
            super(Test, self).__init__(**kwargs)
     
            self.data = self.datas()
    
        # Homepage Screen
        def homepage(self, screenmanager):        
            
            screenmanager.current = 'homepage_screen'
            Clock.schedule_once(self.clear_widgets)
    
        # Clear Widgets
        def clear_widgets(self, *args):
    
            for child in [child for child in self.ids.gridsonuc.children]:
                self.ids.gridsonuc.remove_widget(child)      
    
        # Under Over Screen
        def second(self,screenmanager):
            
            screenmanager.current = 'second_screen'
    
            Clock.schedule_once(self.clear_widgets)
            Clock.schedule_once(self.datas) # Before calculation, each time app pulls data again, but Kivy Does Not Update The Refreshed Data in The Screen!    
            Clock.schedule_once(self.calculate)
    
            # or, if i can use threading system as well but this time i must add @mainthread above def calculate(self, *args): to make code work.
            # in both scenario, Kivy Does Not Update The Refreshed Data in The Screen While APP is Running.
    
            # mythread1 = threading.Thread(target=self.clear_widgets) 
            # mythread1.start()
            # mythread2 = threading.Thread(target=self.datas) 
            # mythread2.start()
            # mythread3 = threading.Thread(target=self.calculate) 
            # mythread3.start()
    
        # Calculation
        #@mainthread
        def calculate(self, *args):        
    
            
            for i in self.data['home']:           
    
                box = BoxLayout(size_hint_y = None, height = dp(50))
                hometeams = Label(text = f'{[i]}', font_name = 'Roboto', font_size = dp(15), size_hint = (0.225, 1), halign='center', bold = True )
                box.add_widget(hometeams)
                self.ids.gridsonuc.add_widget(box)
    
        def datas(self, *args):           
            
            # PLEASE CHANGE THE LOCATION!!!!!!!!!!!!!!!!!
            with open ("C:\Users\Messi\Desktop\Python\Projects\Football Tips\Kivy\Testing Bugs\Test1\data.json", "r") as dosya:
            
                dataApi = json.load(dosya)      
                print('datas updated')
            return dataApi     
      
    class TestApp(App):
        def build(self): 
            return Test()
    
    if __name__ == '__main__':
        TestApp().run()

KV File:

#:import NoTransition kivy.uix.screenmanager.NoTransition
<Test>:
    ScreenManager:
        transition: NoTransition()
        id: sm
        size: root.width, root.height
        Screen:
            name: 'homepage_screen'            
            BoxLayout:
                size_hint: 1, 0.10
                Button:
                    text: 'Calculate'
                    id: underOver_button_homepage
                    on_press: root.second(sm)     
                    background_color: 0, 0, 0, 0                                  
        Screen:
            name: 'second_screen'
            BoxLayout:
                spacing: '20dp'
                orientation: 'vertical'    
                BoxLayout:
                    size_hint: 1, 0.80
                    ScrollView:
                        scroll_type: ['bars', 'content']
                        bar_margin: '5dp'
                        bar_color: 1, 0.4, 0.769, 1 
                        bar_width: '5dp'
                        bar_inactive_color: 1, 0.4, 0.769, 1
                        GridLayout:                            
                            id: gridsonuc
                            cols: 1
                            spacing: '50dp'
                            size_hint_y: None
                            height: self.minimum_height        
                BoxLayout:
                    size_hint: 1, 0.10
                    Button:
                        text: 'Home'
                        id: home_button_underOver
                        on_press: root.homepage(sm)
                        background_color: 0, 0, 0, 0                 

data.json File

Please create a data.json file and PLEASE CHANGE THE LOCATION!!!!!!!!!!!!!!!!! in def datas(self, *args):
with open ("C:UsersMessiDesktopPythonProjectsFootball TipsKivyTesting BugsTest1data.json", "r") as dosya:

{"home": ["Manchester City", "Arsenal"]}

Video Of The Problem
https://www.youtube.com/watch?v=mMwryGLQ5SQ

Thanks for your help