KivyMD屏幕管理器输出不稳定

Question

我需要使用kivyMD构建应用程序。我已经尝试了很多资源，但是一次又一次遇到相同的问题。下面的代码运行，但是输出变得模糊且重复，如输出图像中所示。

First screen On clicking the button

from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty, StringProperty
from kivymd.uix.label import MDLabel


class LayoutClass(BoxLayout):
    s_manager = ObjectProperty(None)
    tf_word = StringProperty('')

    def change_screen(self, screen, *args):
        self.s_manager.current = screen


KV = """
LayoutClass:
    s_manager:s_manager
    orientation: 'vertical'
    ScreenManager:
        id: s_manager
        word_screen: word_screen
        meaning_screen: meaning_screen
                
        Screen:
            id: word_screen
            name: 'word_screen'
            tf_word:tf_word
            
            MDTextField:
                id: tf_word
                name: 'tf_word'
                hint_text: 'Enter the Word'
                halign: "center"
            MDRectangleFlatButton:
                text: 'Search'
                on_press: root.change_screen('meaning_screen')
                    
        
        Screen:
            id: meaning_screen
            name: 'meaning_screen'
                    
            MDLabel:
                text: "Meaning"                                                    
"""


class TestApp(MDApp):
    def __init__(self, **kwargs):
        self.title = "wordie-DEV"
        super().__init__(**kwargs)

    def build(self):
        self.root = Builder.load_string(KV)


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