IsAvailable always false with Kinect Studio on IsAvailableChanged - wpf

Question

Environ: Kinect 2.0 SDK, Kinect Studio, Windows 10, WPF
e.IsAvailailable is always returning false when I'm driving my programming via the Kinect Studio ( https://msdn.microsoft.com/en-us/library/microsoft.kinect.kinectsensor.isavailable.aspx ). I would think it would return true if it were receiving data. Note the BodyReader frames are arriving even though the sensor started unavailable and never tripped the IsAvailableChanged handler. Note the BodyBasics-WPF SDK 2.0 sample behaves the same way.
A number of code samples stop if they get e.IsAvailable=false. Probably a bad move if you are using Kinect Studio and playback.
Bug? Feature? Lack of documentation?
Kinect against Kinect Studio - IsAvailable = false
Kinect against Physical Kinect - IsAvailable = true
Code and XAML below...
public partial class MainWindow : Window
{
private KinectSensor m_kinectSensor = null;
private BodyFrameReader m_bodyReader;
private Body[] m_bodies = null;
public MainWindow()
{
this.m_kinectSensor = KinectSensor.GetDefault();
this.m_kinectSensor.IsAvailableChanged += KinectSensor_IsAvailableChanged;
this.m_kinectSensor.Open();
// hook the body stuff
this.m_bodyReader = m_kinectSensor.BodyFrameSource.OpenReader();
this.m_bodyReader.FrameArrived += BodyReader_FrameArrived;
InitializeComponent();
Msg("MainWindow c'tor completed");
}
private void BodyReader_FrameArrived(object sender, BodyFrameArrivedEventArgs e)
{
Msg(String.Format("BodyReader_FrameArrived: {0}" , e.FrameReference.RelativeTime.ToString()));
}
private void KinectSensor_IsAvailableChanged(object sender, IsAvailableChangedEventArgs e)
{
System.Diagnostics.Debug.WriteLine( "KinectSensor_IsAvailableChanged: e.IsAvailable=" + e.IsAvailable.ToString() );
TextBlock_StatusBar.Text = "KINECT SENSOR STATUS: " + e.IsAvailable.ToString();
}
private void Msg ( string s )
{
if (s.Length <= 0) s = "ready";
TextBlock_Msg.Text = s;
}
}
}
XAML
<Window x:Class="FaceNSkinWPF.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:FaceNSkinWPF"
mc:Ignorable="d"
Title="MainWindow"
Height="600" Width="800"
>
<Grid Margin="10,10,10,10">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Orientation="Horizontal" HorizontalAlignment="Center">
<Button Content="ButtonOne" Width="150" Height="30" Margin="10"/>
<Button Content="ButtonOne" Width="150" Height="30" Margin="10"/>
<Button Content="ButtonOne" Width="150" Height="30" Margin="10"/>
</StackPanel>
<Viewbox Grid.Row="1" HorizontalAlignment="Center">
<Image Source="{Binding ImageSource}" Stretch="UniformToFill" />
</Viewbox>
<StackPanel Grid.Row="2" Orientation="Vertical">
<TextBlock x:Name="TextBlock_StatusBar" Height="20" Foreground="Black" FontWeight="Bold" Text="KINECT SENSOR STATUS: unknown"/>
<TextBlock x:Name="TextBlock_Msg" Height="20" Foreground="Blue" FontWeight="Bold" Text="ready"/>
</StackPanel>
</Grid>