Example #1 (Works):

<ScrollView x:Name="svMain" Grid.Row="0">
    <Grid Margin="20" x:Name="gridSV">
        <VerticalStackLayout Grid.Row="2" x:Name="vslFooter" VerticalOptions="End">
            <local:Paginator x:Name="localPaginator" Paginate="localPaginator_Paginate"></local:Paginator>
        </VerticalStackLayout>
    </Grid>
</ScrollView>

When the last page is tapped from the <local:Paginator />, the data is pulled and the BindableProperty is updated. Then (svMain as IView).InvalidateMeasure(); is triggered which properly updates the view based on the number of results, shortening the page length.

Code behind:

private async void localPaginator_Paginate(object sender, PaginateEventArgs e)
{
    await svMain.ScrollToAsync(0, 0, false);
    await LoadPosts(e.GoToPageNo);
    (svMain as IView).InvalidateMeasure();
}

Example #2 (Not Working):

<RefreshView x:Name="rvMain" Grid.Row="0" IsRefreshing="{Binding IsRefreshing}" Command="{Binding RefreshCommand}" RefreshColor="{DynamicResource Primary}">
    <ScrollView x:Name="svMain" Grid.Row="0">
        <Grid Margin="20" x:Name="gridSV">...</Grid>
    </ScrollView>
</RefreshView>

When the RefreshView Command runs, it updates the data for the BindableProperty. Here is the code behind for the RefreshView.Command:

ICommand refreshCommand = new Command(async () =>
{
    rvMain.IsRefreshing = true;
    await LoadResults(PageNo);
    rvMain.IsRefreshing = false;
    (svMain as IView).InvalidateMeasure();
});
rvMain.Command = refreshCommand;

However, (svMain as IView).InvalidateMeasure(); does not reset the height of the ScrollView. So there seems to be an issue with InvalidateMeasure() on the ScrollView when within a RefreshView.

Am I maybe calling (svMain as IView).InvalidateMeasure(); too soon? I tried adding a delay and also a background task for InvalidateMeasure(), but neither worked.