FontSize is not consistent between TextBlock and TextBox since WinAppSDK 1.6

[rudyhuyn]

Describe the bug

Since the update to WinAppSDK 1.6, there is an inconsistency between TextBlock and TextBox controls regarding FontSize (and LineHeight when the FontSize is increased to match). This discrepancy results in misalignment and rendering issues, impacting the visual consistency of text across different controls.

Steps to reproduce the bug

Create a new application with WinAppSDK 1.6 and add the following XAML. Observe that the FontSize does not match.

    <StackPanel HorizontalAlignment="Center" Width="500" VerticalAlignment="Center">
        <TextBox
            x:Name="InputText"
            Height="200"
            AcceptsReturn="True"
            TextWrapping="Wrap" />

        <Grid Height="200" Margin="0,12,0,0">
            <TextBox
                x:Name="ResultTextBox"
                Padding="12"
                AcceptsReturn="True"
                FontSize="13"
                Foreground="#80ff0000"
                Text="{x:Bind InputText.Text, Mode=OneWay}"
                TextWrapping="Wrap" />
            <TextBlock
                x:Name="ResultTextBlock"
                Padding="13"
                FontSize="13"
                Foreground="#800000ff"
                Text="{x:Bind InputText.Text, Mode=OneWay}"
                TextWrapping="Wrap" />
        </Grid>
    </StackPanel>

Expected behavior

FontSize of TextBlock and TextBlock should be consistent

Screenshots

Red: TextBox
Blue: TextBlock

WinAppSDK 1.5:

WinAppSDK 1.6:

NuGet package version

Windows App SDK 1.6.0: 1.6.240829007

Packaging type

Packaged (MSIX), Unpackaged

Windows version

Insider Build (xxxxx)

IDE

Visual Studio 2022

Additional context

No response