SelectionChanged event is not working in case of footnote in word document

Hi

I have a desktop application that will search some text in word document and show in right hand side pane. and on selection of particular finding it will highlight the text in word doc.

but if the document is having some footnote then selection change is not working properly, the text is not getting highlighted in the footnote.

whats the difference in normal text and footnote selection. how do I handle this.

private void Grid_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (Grid.SelectedItem != null)
            {
                this.SelectedIndex = Grid.SelectedIndex;
            }
            e.Handled = true;

        }