Xamarin forms listview items not fully shown - xaml

Question

I have this Xamarin listview:
<ContentPage.Content>
<ScrollView>
<StackLayout Padding="20,20,20,20">
<Grid>
<StackLayout Margin="10">
<Label Text="Quoting and Tankering" Style="{DynamicResource TitleStyle}" Margin="0, 20" HorizontalTextAlignment="Center" />
<Label Text="Select Aircraft:" />
<Picker Margin="30, 0, 0, 30" x:Name="pickerAircraft" ItemDisplayBinding="{Binding TailNumber}" SelectedItem="{Binding Id}" SelectedIndexChanged="PickerAircraft_SelectedIndexChanged" Title="Aircraft Selector"></Picker>
<Button Text="Add Leg" Margin="10,10,10,10" TextColor="Green" Clicked="Button_Clicked_1" />
<ListView ItemsSource="{Binding .}" VerticalOptions="Center">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Padding="10,10,10,10" HeightRequest="100">
<Label Text="Leg" />
<StackLayout Orientation="Horizontal" HeightRequest="100">
<Entry x:Name="txtICAO" WidthRequest="30" Text="{Binding ICAO}" />
<Button Text="Delete" WidthRequest="50" Clicked="Button_Clicked_2" x:Name="btn_Delete_Item_In_Cart" />
</StackLayout>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Button Text="Go to Step 2"
VerticalOptions="CenterAndExpand"
HorizontalOptions="Center"
Clicked="Button_Clicked" />
</StackLayout>
</Grid>
</StackLayout>
</ScrollView>
</ContentPage.Content>
Now, when I'm rendering the page the listview items are partially shown, please check the screenshot:
What am I doing wrong with the listview? Do I need to add some margin/padding in order to have the full size shown?
Also the button below the listview is not shown.