What layout structure is recommended to avoid whitespace and scrolling issues when using CollectionView on iOS?

Place the CollectionView directly in a Grid row with Height=”*”, or inside a well-bounded AbsoluteLayout zone. Avoid wrapping it in a ScrollView or StackLayout that allows infinite height.

<Grid RowDefinitions="Auto,*">
  <BoxView Grid.Row="0" HeightRequest="56"/>
  <CollectionView Grid.Row="1" ItemsSource="{Binding Items}" />
</Grid>