Xamarin Forms: Can't align Frame/Entry and Button in a grid

Question

I have a Frame around an Entry and a button in a grid. However, I can't get the frame/entry to fill up or center next to the button.

Here's my xaml:

<StackLayout>
        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Frame Grid.Column="0" BorderColor="{DynamicResource PrimaryColor}" CornerRadius="5" IsClippedToBounds="True"
                   Padding="0" Margin="10,10,5,5" VerticalOptions="CenterAndExpand" HasShadow="False">
                <Entry x:Name="queryEntry" Text="{Binding QueryString}" FontSize="{DynamicResource StandardLabelFontSize}" 
                    Placeholder="Search string" ReturnType="Search" ClearButtonVisibility="WhileEditing" 
                    VerticalOptions="CenterAndExpand" AutomationId="TextSearchEntry" BackgroundColor="#F0F0F0"/>
            </Frame>
            <Button Grid.Column="1" Text="Find" Command="{Binding FindTextCommand}" Margin="0,10,10,0" WidthRequest="80"
                    Padding="0" IsEnabled="{Binding QueryString, Converter={StaticResource NonEmptyStringValue}}"
                    VerticalOptions="Center"/>
        </Grid>
        <Label Text="No Results Found." HorizontalTextAlignment="Center" IsVisible="{Binding WereNoResultsFound}"/>
        <ScrollView>
            <CollectionView ItemsSource="{Binding Items}" SelectionMode="None" >
                <CollectionView.ItemTemplate>

Here's how it's laying out on iOS:

If you notice that both of the controls are starting at the top of the row but the button is taller. I would like to have them both automatically be the same height. I've tried many different settings but can't seem to get it to work. I thank anyone in advance for assistance.