How to solve overalpping probkem in Listview item ?

Hi, I am working on xamarin forms, where I have a binding list view item dynamically from the API for dynamic menus but the list view is overlapping the other item. Please refer to the below images.

When menus bind first without expand.

two menus are there, If I click on first menu it looks like

it is overlapping with second menu.

If I expand the 2nd menu then it looks like

My UI code is

`<ContentPage.Content>

    <ListView x:Name="Menusource" ItemsSource="{Binding MainMenues}" SeparatorVisibility="None" HasUnevenRows="true"  SelectionMode="Single">
        <ListView.ItemTemplate>
            <DataTemplate>
                <ViewCell>
                    <StackLayout Orientation="Vertical">
                        <Grid Padding="15">
                            <Label Text="{Binding MenuName}"  FontSize="16" VerticalOptions="Center" HorizontalOptions="Start"/>
                            <Image x:Name="im" Source="{Binding ArrowIconSource}" IsVisible="{Binding IsSubmenu}" HeightRequest="15" WidthRequest="15" VerticalOptions="Center" 
                                       HorizontalOptions="End">
                            </Image>
                            <Grid.GestureRecognizers>
                                <TapGestureRecognizer 
                                            Tapped="MainMenuTapped"
                                            NumberOfTapsRequired="1" />
                            </Grid.GestureRecognizers>
                        </Grid>
                        <Grid Padding="5,0,0,0" Margin="15,0,0,0" IsVisible="{Binding IsChildrenVisible}" HeightRequest="{Binding ChildrenRowHeightRequest}">
                            <ListView ItemsSource="{Binding Submenues}" ItemTapped="SubMenuTapped" SeparatorVisibility="None" SelectionMode="Single" HasUnevenRows="false">
                                <ListView.ItemTemplate>
                                    <DataTemplate>
                                        <ViewCell>
                                            <Grid Padding="10">
                                                <Label Text="{Binding SubMenuTitle}"  VerticalOptions="Center" HorizontalOptions="Start" />
                                                <Image IsVisible="False" Source="rightarrow.png" HeightRequest="12" WidthRequest="12" VerticalOptions="Center" HorizontalOptions="End"/>
                                                <BoxView VerticalOptions="EndAndExpand" HorizontalOptions="FillAndExpand" HeightRequest="1" WidthRequest="30" Color="#5b5d68"></BoxView>
                                            </Grid>
                                        </ViewCell>
                                    </DataTemplate>
                                </ListView.ItemTemplate>
                            </ListView>
                        </Grid>
                        <!--<BoxView VerticalOptions="Center" HorizontalOptions="Center" HeightRequest="1" WidthRequest="50" Color="#5b5d68"></BoxView>-->
                    </StackLayout>
                </ViewCell>
            </DataTemplate>
        </ListView.ItemTemplate>
    </ListView>

    <StackLayout VerticalOptions="End" BackgroundColor="#fa4e0a">
        <Button TextColor="White" x:Name="Btn_Logout" Text="Logout" Clicked="Btn_Logout_Clicked" BackgroundColor="#fa4e0a"></Button>
    </StackLayout>
</StackLayout>
</ContentPage.Content>`

How to overcome from this problem?