[UWP] Webview not scrolling inside of Frame

Description

A nested WebView in unable to scroll within a Frame, in Xamarin Forms, running in UWP

<ContentPage.Content>
    <Frame >
        <Grid>
            <WebView Source="https://www.microsoft.com" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"/>
        </Grid>
    </Frame>
</ContentPage.Content>

Code without the frame works as expected

<ContentPage.Content>
    <Grid >
        <WebView Source="https://www.microsoft.com" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"/>
    </Grid>
</ContentPage.Content>

Known Workaround - If you add an outline color to the frame, the webview becomes scrollable

<ContentPage.Content>
    <Frame OutlineColor="White">
        <Grid >
            <WebView Source="https://www.microsoft.com" VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"/>
        </Grid>
    </Frame>
</ContentPage.Content>

Theory: An issue is related to input transparency ?

Steps to Reproduce

1. Create new Xamarin Forms, UWP app
2. Paste code listed above
3. Test - Attempt to scroll webview
4. Add supplied workaround
5. Test - Attempt to scroll webview

Expected Behavior

Webview to scroll regardless of outer container

Actual Behavior

Webview does not scroll unless you add a OutlineColor to the Frame

Basic Information

• Version with issue:
• IDE: Visual Studio 2017
• Platform Target Frameworks: UWP
• Nuget Packages: Xamarin.Forms 3.4