WPF, TextBlock with RotateTransform & LinearGradientBrush

Question

I have textblock like this

<TextBlock Text="BETA"
            FontSize="28"
            HorizontalAlignment="Right"
            VerticalAlignment="Center"
            Margin="0,17,420,271"
            FontFamily="Georgia">
    <TextBlock.RenderTransform>
        <RotateTransform Angle="20" />
    </TextBlock.RenderTransform>
    <TextBlock.Foreground>
        <LinearGradientBrush StartPoint="0,0"
                                EndPoint="0,24"
                                MappingMode="Absolute">
            <GradientStopCollection>
                <GradientStop Color="White"
                                Offset="0" />
                <GradientStop Color="Orange"
                                Offset=".2" />
                <GradientStop Color="DarkOrange"
                                Offset=".85" />
                <GradientStop Color="White"
                                Offset="1" />
            </GradientStopCollection>
        </LinearGradientBrush>
    </TextBlock.Foreground>
</TextBlock>

It won't render any text. If I remove the transform OR the brush then it works fine but both together won't render anything.

Answer 1

Removing Absolute as the mapping mode fixed my issue? Not sure why.