Phantom ShellGroupItem being added to MainPage.InternalChildren list - xamarin.forms

Question

I am using Xamarin.Forms Shell Layout, with a Flyout menu using Custom subclassed FlyoutItem called CustomFlyoutItem, the display of which is controlled with a dataitem template. The template uses a Grid and contains two rows. The second row is just a pink bottom border (BoxView height 1) and should only be displayed if my customFlyoutItem's bool property HasBottomDivider is set to true. (Using the IsVisible binding to achieve this).
There are two issues: 1) The last item in the flyout item should be the "help" item in my screenshot. However the list appears to contain one extra phantom CustomFlyoutItem with no icon or text. On debugging I see this is an item of the type "ShellGroupItem"
2) the item is getting a pink border under it too somehow which is the main issue really.
I have a workaround to remove the item using linq before the page is displayed, but I would like to know the root cause of why it is there in the first place.
<Shell.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="0.05*"></ColumnDefinition>
<ColumnDefinition Width="0.1*"></ColumnDefinition>
<ColumnDefinition Width="0.85*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="45" />
<RowDefinition Height="1" />
</Grid.RowDefinitions>
<Label Text="{Binding Ligature}"
Grid.Column="1"
Grid.Row="0"
TextColor="White"
FontFamily="{Binding FontFamily }"
VerticalTextAlignment="Center"
HorizontalTextAlignment="Start"
FontSize="20"
HeightRequest="45">
</Label>
<Label Grid.Column="2"
Grid.Row="0"
FontSize="16"
Margin="0"
Text="{Binding Title}"
TextColor="White"
HorizontalTextAlignment="Start"
VerticalTextAlignment="Center" />
<BoxView IsVisible="{Binding HasBottomDivider}"
BackgroundColor="{StaticResource BrilliantRose}"
Grid.Column="0" Grid.ColumnSpan="3"
Grid.Row="1" >
</BoxView>
</Grid>
</DataTemplate>
</Shell.ItemTemplate>
<Shell.FlyoutHeader>
<menu:FlyoutHeader />
</Shell.FlyoutHeader>
<menu:CustomFlyoutItem Title="Home" FontFamily="{StaticResource FontAwesomeSolid}" Ligature="{x:Static fontawesome:FontAwesomeIcons.Home}">
<Tab>
<ShellContent>
<views:LoginPage />
</ShellContent>
</Tab>
</menu:CustomFlyoutItem>
<menu:CustomFlyoutItem HasBottomDivider="true" Title="Measurements" FontFamily="{StaticResource FontAwesomeRegular}" Ligature="{x:Static fontawesome:FontAwesomeIcons.ChartBar}">
<Tab>
<ShellContent>
<views:LoginPage />
</ShellContent>
</Tab>
</menu:CustomFlyoutItem>
<menu:CustomFlyoutItem Title="Jobs" FontFamily="{StaticResource FontAwesomeSolid}" Ligature="{x:Static fontawesome:FontAwesomeIcons.User}">
<Tab>
<ShellContent>
<views:LoginPage />
</ShellContent>
</Tab>
</menu:CustomFlyoutItem>
<menu:CustomFlyoutItem HasBottomDivider="true" Title="Instruments" FontFamily="{StaticResource FontAwesomeBrands}" Ligature="{x:Static fontawesome:FontAwesomeIcons.BluetoothB}">
<Tab>
<ShellContent>
<views:LoginPage />
</ShellContent>
</Tab>
</menu:CustomFlyoutItem>
<menu:CustomFlyoutItem Title="Settings" FontFamily="{StaticResource FontAwesomeSolid}" Ligature="{x:Static fontawesome:FontAwesomeIcons.Cog}">
<Tab>
<ShellContent>
<views:LoginPage />
</ShellContent>
</Tab>
</menu:CustomFlyoutItem>
<menu:CustomFlyoutItem Title="Help" FontFamily="{StaticResource FontAwesomeSolid}" Ligature="{x:Static fontawesome:FontAwesomeIcons.QuestionCircle}">
<Tab>
<ShellContent>
<views:LoginPage />
</ShellContent>
</Tab>
</menu:CustomFlyoutItem>
public class CustomFlyoutItem : FlyoutItem
{
public string FontFamily { get; set; }
public string Ligature { get; set; } = "";
public bool HasBottomDivider { get; set; } = false;
}