ListView inside ScrollView difference between Android and iOS

This is the code:

Content = new ScrollView () {
                VerticalOptions = LayoutOptions.Fill,
                Content = new StackLayout () {
                    VerticalOptions = LayoutOptions.Fill,
                    Children = {
                        this.ListOfComments,
                        CommentArea
                    }
                }
            };

The ListView:

readonly ListView ListOfComments = new ListView () {
            HasUnevenRows = true,
            SeparatorVisibility = SeparatorVisibility.None,
            IsPullToRefreshEnabled = true, 
            IsRefreshing = true,
        };

The expected result is this (Android):

On iOS is not the same:

Why?