wpf - ScrollViewer does not react to ScrollToHorizontalOffset(0)

Question

My ScrollViewer is auto scrolling to a middle offset, even when I try to force it back to a 0 offset it still aligns incorrectly

Here is part of the XAML:

<ScrollViewer x:Name="ScrollView" Grid.Row="0" Grid.Column="0" VerticalScrollBarVisibility="Auto">
        <TreeView Grid.ColumnSpan="2" Name="LOBSummaryTree" 
                      BorderThickness="0" DataContext="{Binding}">
        <TreeView.Resources>
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent"/>
            <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
            <common:VisibilityConverter x:Key="VisibilityConverter"/>
            <common:TextStyleConverter x:Key="TextStyleConverter"/>
            <Style TargetType="{x:Type TreeViewItem}">
                <Setter Property="HeaderTemplate">
                    <Setter.Value>
                        <DataTemplate DataType="ContentPresenter">
                            <StackPanel x:Name="StackGroups" Orientation="Horizontal">
                                <TextBlock Name="txtBox" Tag="{Binding}">

And the attempt from the code behind to force the offset:

var scrollViewer = this.ScrollView;
if (scrollViewer != null)
{
   scrollViewer.InvalidateScrollInfo();
   scrollViewer.ScrollToHorizontalOffset(0);
   UpdateLayout();
}

What am I doing incorrectly, I want the alignment of the horizontal scollbar to be forced to the left on the initial load of the treeview?