ProgressAnimation in a WebView does not work as expected on iOS

[eksperts]

Reported on community.
Fuse 1.2.1 build 13974, macOS.

Affected target: iOS, both preview and build.
Not affected: Android.

<App>
<Panel ux:Class="LoadingBar" Width="0%" Height="10" Color="#fc0" Alignment="Left" />

<DockPanel>
    <StatusBarBackground Dock="Top" />
    <LoadingBar Dock="Top" ux:Name="_loadingBar" />
    <NativeViewHost Dock="Fill">
        <WebView Url="https://www.fusetools.com/">
            <ProgressAnimation>
                <Change _loadingBar.Width="100%" />
            </ProgressAnimation>
            <WhileLoading>
                <!-- active while a page is loading -->
            </WhileLoading>
        </WebView>
    </NativeViewHost>
</DockPanel>
</App>

On Android this works as expected: the ProgressAnimation runs for every page being loaded as you keep clicking on links. The LoadingBar width changes to 0, and then progresses to 100% as the page loads.

On iOS, the ProgressAnimation only runs for the first page, and clicking on further links does not have any effect on the width of LoadingBar.

Is this an OS-specific WebView thing, or is there something we can do to make the two work the same?

[fusebuild]

The forum thread Webview progressbar posted by Palton was linked to this issue.