How to solve overlapping list-view item problem?

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 to looks like below image.

If I click on the first menu it looks like

this one is overlapping with second item.

If I expand the Second menu it looks like

My code
`<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 solve this?