Microsoft released a new version of Windows 10 UWP SDK Build 17763, you can check the What's New document for more details. But when I retarget my App to version 17763, something unexpected happens, the AcrylicBrush gone missing if I change my App runtime to version 17763.

I am not sure if this is by design on 17763 or it is a bug, I am trying to contact Microsoft product group on this problem. For now, I can address a workaround for this problem.

If you don't understand the problem I am talking about, here's a simple test.

Create a new blank App, use 17134 for both Min and Target runtime.

Add a basic NavigationView control into MainPage.

<NavigationView IsSettingsVisible="True">
        <NavigationViewItem Content="Main" Icon="Document" />

Run the App, you should get a fine NavigationView control with correct AcrylicBrush:

Now, change the target version to 17763

Run the App again, the AcrylicBrush is gone:

To fix this, I have to use a workaround by overriding the pane's background. Add this code in App.xaml

    <AcrylicBrush x:Key="NavigationViewDefaultPaneBackground"
                  BackgroundSource="Backdrop" TintColor="{ThemeResource SystemChromeMediumColor}" TintOpacity=".5"/>
    <AcrylicBrush x:Key="NavigationViewTopPaneBackground"
                  BackgroundSource="Backdrop" TintColor="{ThemeResource SystemChromeMediumColor}" TintOpacity=".5"/>
    <AcrylicBrush x:Key="NavigationViewExpandedPaneBackground"
                  BackgroundSource="HostBackdrop" TintColor="{ThemeResource SystemChromeMediumColor}" TintOpacity=".7"/>

Now you should get an AcrylicBrush similar to the origin one on runtime version 17763.

Note: the same problem happens to the NavigationView control in WinUI ( also, even targeting version is 17134.