[WASM] Content for Templated Expander shows only once

[ajpinedam]

Current behavior

When using a Templated Expander, the Expander.Content shows only the first time it is opened. After this, when opening the Content, it shows empty.

uno_platform_expander_templated.mp4

Expected behavior

The content is visible all the time.

How to reproduce it (as minimally and precisely as possible)

<Grid>
	<local:SettingsExpander Header="Hello From Header in Custom Control" IsExpanded="False">
		<local:SettingsExpander.Template>
			<ControlTemplate TargetType="local:SettingsExpander">
				<controls:Expander
				x:Name="PART_Expander"
				MinWidth="{TemplateBinding MinWidth}"
				MinHeight="{TemplateBinding MinHeight}"
				HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
				HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
				CornerRadius="{TemplateBinding CornerRadius}"
				IsExpanded="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
					<controls:Expander.Header>
						<Border Background="Purple">
							<Grid>
								<Grid.RowDefinitions>
									<RowDefinition Height="Auto" />
									<RowDefinition Height="Auto" />
								</Grid.RowDefinitions>
								<TextBlock
								x:Name="PPT_TextBlock"
								FontFamily="{TemplateBinding FontFamily}"
								FontSize="28"
								Foreground="Red"
								Text="{TemplateBinding Header}" />
								<TextBlock
								Grid.Row="1"
								FontFamily="{TemplateBinding FontFamily}"
								FontSize="14"
								Foreground="White"
								Text="On the Header" />
							</Grid>
						</Border>
					</controls:Expander.Header>
					<controls:Expander.Content>
						<Border Background="Gray">
							<Grid>
								<Grid.RowDefinitions>
									<RowDefinition Height="Auto" />
									<RowDefinition Height="Auto" />
								</Grid.RowDefinitions>
								<TextBlock
								x:Name="PPT_TextBlock2"
								FontFamily="{TemplateBinding FontFamily}"
								FontSize="28"
								Foreground="Red"
								Text="{TemplateBinding Header}" />
								<TextBlock
								Grid.Row="1"
								FontFamily="{TemplateBinding FontFamily}"
								FontSize="14"
								Foreground="White"
								Text="On the Content" />
							</Grid>
						</Border>
					</controls:Expander.Content>
				</controls:Expander>
			</ControlTemplate>
		</local:SettingsExpander.Template>
	</local:SettingsExpander>
</Grid>

Workaround

N/A

Works on UWP/WinUI

None

Environment

Uno.WinUI / Uno.WinUI.WebAssembly / Uno.WinUI.Skia

NuGet package version(s)

No response

Affected platforms

WebAssembly

IDE

Visual Studio 2022

IDE version

No response

Relevant plugins

No response

Anything else we need to know?

No response