With this code (`Editor.Document.Selection.CharacterFormat.Size = 20;`) I change the font size of a UWP `RichEditBox` in the `Page_Loaded`-handle. When I start typing some characters, everything works fine. But when I select the paragraph mark and then type something, this text appears in the wrong font size (10.5). 

What I've tried is to expand the selection before setting the font size, but it seems that there is no paragraph mark when there's no text. But when the rich edit box is empty and I press `Shift+Right Arrow ⟶` (as I would normally select the paragraph mark), the font size is set back to 10.5.

Is there any workaround to prevent that the font size is set back to 10.5 in any case?

```
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <TextBlock x:Name="FontSizeBlock" Grid.Row="0"></TextBlock>
    <RichEditBox x:Name="Editor" Grid.Row="1" SelectionChanged="HandleRichEditBox_SelectionChanged"></RichEditBox>
</Grid>

public sealed partial class MainPage : Page {
    public MainPage() {
        this.InitializeComponent();
        this.Loaded += Page_Loaded;
    }

    private void Page_Loaded(object sender, RoutedEventArgs e) {
        Editor.Document.Selection.SetRange(0, 1);
        Editor.Document.Selection.CharacterFormat.Size = 20;
    }

    private void HandleRichEditBox_SelectionChanged(object sender, RoutedEventArgs e) {
        FontSizeBlock.Text = "FontSize: " + Editor.Document.Selection.CharacterFormat.Size;
    }
}

```

[![enter image description here](https://i.stack.imgur.com/gJeGW.gif)](https://i.stack.imgur.com/gJeGW.gif)