Bound ListView displaying wrong items - caliburn.micro

Question

I have a simple ListView bound to a BindableCollection (async ObservableCollection). I am populating the BindableCollection in an async method. After a refresh, the collection contains about 130 unique items. However, the ListView displays many of the items repeatedly. Checking the actual contents of the collection, I can see they are definitely unique. The contents are something like the following
mazzy star
neil young
the babies
haunted leather
alice boman
compilations
richard swift
rolling stones
fleetwood mac
future islands
lily & madeleine
darlenya
darlenya (different from last)
father john misty
eels
sharon van etten
feeding people
helado negro
neil young first repeat
the babies
haunted leather
alice boman
compilations
richard swift
rolling stones
fleetwood mac
future islands
lily & madeleine
darlenya
darlenya (different from last)
father john misty
eels
sharon van etten
feeding people
helado negro
neil young second repeat
the babies
...
eels
The ViewModel
private readonly BindableCollection<Track> _tracks = new BindableCollection<Track>();
private readonly ITrackFeedService _feedService;
public ICollection<Track> Tracks
{
get { return _tracks; }
}
public async void UpdateTracksAsync()
{
IsBusy = true;
_tracks.Clear();
var tracks = await _feedService.LoadAsync();
_tracks.AddRange(tracks);
IsBusy = false;
}
The View (bound through caliburn.micro convention)
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" Margin="10">
<Grid.RowDefinitions>
<RowDefinition Height="auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<ListView Name="Tracks"
ItemTemplate="{StaticResource TrackDataTemplate}"
Grid.Row="1">
</ListView>
</Grid>
<DataTemplate x:Key="TrackDataTemplate">
<Grid cm:Bind.Model="{Binding}" Margin="0 0 0 5">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition Width="10" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Image Name="Artwork" Height="100" Width="100"/>
<Grid Grid.Column="2">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<TextBlock Name="Title" Style="{StaticResource TrackTextStyle}" />
<TextBlock Name="Artist" Grid.Row="1" Style="{StaticResource TrackTextStyle}" />
<TextBlock Name="Album" Grid.Row="2" />
<TextBlock Name="ReleaseYear" Grid.Row="3" />
<TextBlock Name="Label" Grid.Row="4" />
</Grid>
</Grid>
</DataTemplate>
Feed Service
public Task<IEnumerable<Track>> LoadAsync()
{
var scraper = new TrackWebScraper(URL);
return scraper.Scrape();
}
I've tried replacing BindableCollection with the standard ObservableCollection with the same result. I'm certain my service is returning a collection of unique items. I can see the ListView clearing when the collection is cleared before grabbing the new items. What am I missing?

Answer 1

Try this
_tracks = null;
var tracks = await _feedService.LoadAsync();
_tracks = tracks;