How to avoid ListView item losing focus? - xaml

Question

I have a UserControl that controls scrolling of a ListView, kind of like a custom ScrollBar. The issue occurs when:
An item in the ListView has keyboard focus (i.e. the focus visual is
set on the item)
I grab and drag my control
Make the release outside of the control (e.g. over the ListView)
Result is that the ListView item loses its focus in the same way it would if I had just clicked outside of the ListView. This is not the way a regular ScrollBar behaves and in fact if I have a Button in my control, click that and make the release outside of the control the Button somehow blocks the release event and the ListView item keeps its focus.
I've tried setting CapturePointer in the PointerPressed handler of my UserControl, but the item still loses focus (although the PointerReleased handler of the ListView isn't called).
UserControl:
<Grid x:Name="RootGrid" Background="AliceBlue">
<Button IsTabStop="False">OKOK</Button>
</Grid>
MainPage:
<Grid x:Name="RootGrid" Background="Gray">
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<ListView>
<TextBlock Text="ListViewItem 1" />
<TextBlock Text="ListViewItem 2" />
<TextBlock Text="ListViewItem 3" />
</ListView>
<local:MyControl Grid.Row="1" />
</Grid>
So in the above example:
Press tab so that an item in the ListView is marked with the black focus rectangle
Press the blue area with the mouse, drag to gray area and release
Notice how the black focus rectangle disappears. Repeat the steps above but press the Button instead of pressing the blue area and notice how the black focus rectangle doesn't disappear. I want the same behavior when dragging from the blue area as when dragging from the Button.