Is it a bug in Xamarin StackLayout children.Add, Clear function?

Question

When creating a button statically, there is no problem in clearing and adding the stacklayout. However, there is a problem when dynamically creating a button and clearing and adding it.

Is there anything I need to do separately when creating dynamically? Do I have to create the layout itself in code too?

I don't understand. This is like a bug.

<ContentView x:Name="xMainContentsView" Grid.Row="1" Grid.Column="0" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">  
  
            <ScrollView Orientation="Horizontal" HorizontalOptions="FillAndExpand">  
                <StackLayout x:Name="xView" Margin="35,80,35,80" Spacing="25" Orientation="Horizontal" HorizontalOptions="FillAndExpand">  
                    <Button Text="g02" Clicked="Button_Clicked"></Button>                     
                </StackLayout>  
            </ScrollView>  
              
            <!--<StackLayout x:Name="xPageView"  Orientation="Horizontal" HorizontalOptions="FillAndExpand">  
            </StackLayout>-->  
</ContentView>  
  
  
private void Button_Clicked(object sender, EventArgs e)  
        {  
            xView.Children.Clear();  
            xView.Children.Add(new Spectrum(this));  
        }  
  
  
  
  
private void InitializeCompView()  
        {  
                
            foreach (MainViewMeasureType contents in Enum.GetValues(typeof(MainViewMeasureType)))  
            {  
                CtrlButton button = new CtrlButton  
                {  
                    WidthRequest = 180,  
                    HeightRequest = 180,  
                    Text = contents.ToString(),  
                    ClassId = contents.ToString(),  
                };  
                button.Pressed += BtnMainContentClick;  
  
                xView.Children.Add(button);  
            }   
        }  
          
  
  
  
private void BtnMainContentClick(object sender, EventArgs e)  
        {  
                xView.Children.Clear();  
                xView.Children.Add(new Spectrum(this));  
         }