GridSplitter with ShowPreview=True not working in P7

[rabbitism]

Describe the bug
As described in title. Preview indicator will be stuck in GridSplitter region.

To Reproduce
Steps to reproduce the behavior:

Add below to sandbox main window.

  <Grid
            Width="300"
            Height="300"
            RowDefinitions="*, Auto, *">
    <Border
        HorizontalAlignment="Stretch"
        Background="#FEFBCB"
        CornerRadius="10" />
    <GridSplitter Grid.Row="1" ShowsPreview="True" />
    <Border
        Grid.Row="2"
        HorizontalAlignment="Stretch"
        Background="#FEFBCB"
        CornerRadius="10" />
  </Grid>

Expected behavior
A clear and concise description of what you expected to happen.
Preview indicator should move freely.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Windows
• Version: 11.0.0-preview 7

Additional context
Add any other context about the problem here.

[grokys]

Caused by problems with adorner clipping in 11.0-previews: #10701.

[rabbitism]

Caused by problems with adorner clipping in 11.0-previews: #10701.

Yeah i also reported #10700, the behavior changes in these previews.

[rabbitism]

Fixed looong time ago. Close.