Stacklayout Inside Stackedlayout Binding IsVisible - xaml

Question

I have a xaml view that is a simple listview which has a couple of stackedlayouts in the cells along with some simple binding of my model:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:directory="clr-namespace:Directory;assembly=Directory"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:models="clr-namespace:Directory.Models"
xmlns:controls="clr-namespace:ImageCircle.Forms.Plugin.Abstractions;assembly=ImageCircle.Forms.Plugin.Abstractions"
xmlns:viewModels="clr-namespace:Directory.ViewModels;assembly=Directory"
x:Class="Directory.Views.DirectoryList">
<ContentPage.BindingContext>
<viewModels:MasterViewModel/>
</ContentPage.BindingContext>
<ListView Margin="0,10"
ItemTapped="ListViewItem_Tabbed"
ItemsSource="{Binding PeopleCollectionGrouped}"
IsGroupingEnabled="True"
GroupDisplayBinding="{Binding Key}"
GroupShortNameBinding="{Binding Key}"
HasUnevenRows="True"
BackgroundColor="White">
<ListView.ItemTemplate>
<DataTemplate x:DataType="models:People">
<ViewCell>
<Grid
Padding="10"
ColumnSpacing="10"
RowSpacing="10">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<controls:CircleImage
Aspect="AspectFill"
BorderColor="Black"
BorderThickness="3"
HeightRequest="66"
HorizontalOptions="CenterAndExpand"
Source="{Binding PhotoUrl}"
VerticalOptions="CenterAndExpand"
WidthRequest="66" />
<StackLayout Grid.Column="1" VerticalOptions="Center">
<Label Text="{Binding FullName}" />
<Label Text="{Binding Location}" />
<StackLayout IsVisible="{Binding IsVisible}"
Orientation="Horizontal"
Margin="0,0,80,0">
<Button Text="Place Order"
WidthRequest="110"
FontSize="15"
BackgroundColor="Chocolate"
TextColor="White"/>
</StackLayout>
</StackLayout>
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
All the bindings work apart from the IsVisible binding which causes the app to crash with:
System.InvalidProgramException: Invalid IL code
If I change my Xaml so that the IsVisible property is not binded and just set to "True" then it compiles and loads.
I have no idea why this isn't working as the other values from the model are binded correctly.
Here is the People model, which "PeopleCollectionGrouped" is of:
public class People
{
[JsonProperty("photo_url")]
public string PhotoUrl { get; set; }
[JsonProperty("location")]
public string Location { get; set; }
[JsonProperty("id")]
public string Id { get; set; }
[JsonProperty("first_name")]
public string FirstName { get; set; }
[JsonProperty("middle_name")]
public string MiddleName { get; set; }
[JsonProperty("last_name")]
public string LastName { get; set; }
public string FullName => $"{FirstName} {LastName}";
public string NameSort
{
get
{
if (string.IsNullOrWhiteSpace(FullName) || FullName.Length == 0)
{
return "?";
}
return FullName[0].ToString().ToUpper();
}
}
public bool IsVisible { get; set; }
}
If anyone can spot where i have gone wrong it would help