Using a custom DependencyProperty extension in XAML causes XamlParseException on property assignment

[Poyo-SSB]

Describe the bug

I'm extending NavigationView with a SettingsItemInfoBadge property (as WinUI does not natively provide this). Trying to use it in XAML causes a XamlParseException with the message "The text associated with this error code could not be found." and "Failed to assign to property 'Example.Utility.Extensions.NavigationViewExtensions.SettingsItemInfoBadge'."

Steps to reproduce the bug

NavigationViewExtensions.cs:

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;

namespace Example.Utility.Extensions;

internal static class NavigationViewExtensions {
    public static readonly DependencyProperty SettingsItemInfoBadgeProperty = DependencyProperty.RegisterAttached("SettingsItemInfoBadge", typeof(InfoBadge), typeof(NavigationViewExtensions), new PropertyMetadata(new InfoBadge(), OnSettingsItemInfoBadgeChanged));

    public static void SetSettingsItemInfoBadge(UIElement element, InfoBadge value) {
        element.SetValue(SettingsItemInfoBadgeProperty, value);
    }

    public static InfoBadge GetSettingsItemInfoBadge(UIElement element) {
        return (InfoBadge)element.GetValue(SettingsItemInfoBadgeProperty);
    }

    private static void OnSettingsItemInfoBadgeChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args) {
        if (sender is not NavigationView navigationView) {
            return;
        }

        if (navigationView.SettingsItem is NavigationViewItem settingsItem) {
            settingsItem.InfoBadge = (InfoBadge)args.NewValue;
        }
    }
}

MainWindow.xaml:

<?xml version="1.0" encoding="utf-8"?>
<Window
    x:Class="Example.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:extensions="using:Example.Utility.Extensions"
    mc:Ignorable="d">

    <NavigationView IsSettingsVisible="True">
        <extensions:NavigationViewExtensions.SettingsItemInfoBadge>
            <InfoBadge/>
        </extensions:NavigationViewExtensions.SettingsItemInfoBadge>
    </NavigationView>
</Window>

Note: using SetSettingsItemInfoBadge() in the code-behind works perfectly fine. OnSettingsItemInfoBadgeChanged() can be empty and still yield the error. In XAML, if <extensions:NavigationViewExtensions.SettingsItemInfoBadge> is empty (i.e. no <InfoBadge> is provided), no error occurs.

Expected behavior

No error should occur or the error provided should be more descriptive.

NuGet package version

WinUI 3 - Windows App SDK 1.5.3: 1.5.240428000

Windows version

Windows 10 (22H2): Build 19045.4291

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