Custom Properties in Custom Control not Displayed in Previewer

I have a custom control with 2 custom properties that I want to see in the Xamarin.Forms Previewer in Visual Studio 2019. Here is the code for the custom control:

using System;
using System.ComponentModel;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace ScorePad
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    [DesignTimeVisible(true)]
    public partial class CheckBox : StackLayout
    {
        public event EventHandler<CheckedChangedEventArgs> CheckedChanged = (sender, e) => { };
        public static readonly BindableProperty TextProperty = BindableProperty.Create("Text", typeof(String), typeof(CheckBox), string.Empty);
        public static readonly BindableProperty IsCheckedProperty = BindableProperty.Create("IsChecked", typeof(bool), typeof(CheckBox), false);

        public string Text
        {
            get => (string)GetValue(CheckBox.TextProperty);
            set => SetValue(CheckBox.TextProperty, value);
        }
        public bool IsChecked
        {
            get => (bool)GetValue(CheckBox.IsCheckedProperty);
            set => SetValue(CheckBox.IsCheckedProperty, value);
        }

        public CheckBox()
        {
            InitializeComponent();
            this.chkCheckBox.CheckedChanged += this.ChkCheckBox_CheckedChanged;
        }

        private void ChkCheckBox_CheckedChanged(object sender, CheckedChangedEventArgs e) { this.CheckedChanged(this, e); }
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<StackLayout x:Class="ScorePad.CheckBox" x:Name="CheckBoxRoot"
    xmlns="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:d="http://xamarin.com/schemas/2014/forms/design"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" BackgroundColor="Black" Style="{StaticResource CheckBoxStackLayoutStyle}">
    <CheckBox x:Name="chkCheckBox" Style="{StaticResource CheckBoxBoxStyle}" BindingContext="{x:Reference CheckBoxRoot}" IsChecked="{Binding IsChecked}"/>
    <Label Style="{StaticResource CheckBoxLabelStyle}" BindingContext="{x:Reference CheckBoxRoot}" Text="{Binding Text}"/>
</StackLayout>

Notice that the 2 custom properties (Text & IsChecked) are databound to the controls in the custom control. However, they do not appear in the Previewer, although they do appear when I debug the app. This is my first custom control, so maybe I'm just forgetting something simple, so any help would be appreciated. Thanks.