Почему не отображается новое значение у Label moneyBalance?

Проверяю полученное значение в MessageBox - оно там есть. Но когда добавляю в контент лейбла - ничего не выводится в нем (смотреть в обработчик Test_Click).

MainWindow:

<Window x:Class="MyWallet.View.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:local="clr-namespace:MyWallet"
    xmlns:vm="clr-namespace:MyWallet.ViewModel"
    mc:Ignorable="d"
    Title="MainWindow" Height="800" Width="1400" WindowStartupLocation="CenterScreen">
<Window.DataContext>
    <vm:MainViewModel/>
</Window.DataContext>
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="350"/>
        <ColumnDefinition/>
    </Grid.ColumnDefinitions>
        <Border Background="Transparent">
            <StackPanel Orientation="Vertical" Background="Transparent">
                <Button Content="Главная" Command="{Binding OpenMainPage}" Click="Test_Click"/>
                <Button Content="Валюта" Command="{Binding OpenCurrencyConverterPage}"/>
            </StackPanel>
        </Border>
    <Grid x:Name="InfoTable" Grid.Column="1">
        <Frame Grid.RowSpan="2" NavigationUIVisibility="Hidden" Content="{Binding CurPage}"/>
    </Grid>
</Grid>

    namespace MyWallet.View
{
    public partial class MainWindow : Window
    {
        public static MainWindow MainWindowLink { get; private set; }
        public MainWindow()
        {
            InitializeComponent();
            MainWindowLink = this;
        }

        private void Test_Click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show(MainMenu.link.CurrencyConverterChangeCur);//просто пробовал устанавливать еще одним способом и проверял получает ли переменная значение
            MessageBox.Show(MainMenu.link.moneyBalance.Content.ToString());//видно что месседж бокс вывел установленное значение и оно правильно, но на экране в лейбле все так же "123"

        }
    }
}

MainMenu:

<Page x:Class="MyWallet.View.MainMenu"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
  xmlns:lvc="clr-namespace:LiveChartsCore.SkiaSharpView.WPF;assembly=LiveChartsCore.SkiaSharpView.WPF"
  xmlns:local="clr-namespace:MyWallet.View"
  mc:Ignorable="d" 
  d:DesignHeight="1000" d:DesignWidth="1200"
  Title="MainMenu" Background="White">

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="1*"/>
        <RowDefinition Height="1.15*"/>
    </Grid.RowDefinitions>
    <TabControl>
        <TabItem x:Name="tabItem1" Header="Расходы" Margin="0 0 0 -5">
            <Grid>
                <Border>
                    <!--<Button Content="123" Click="Test_Click"/>-->
                    <Label x:Name="moneyBalance" Content="123" Width="100" Height="100" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="16" Panel.ZIndex="1"/>
                </Border>
            </Grid>
    </TabItem>
    </TabControl>
</Grid>

.cs:

    namespace MyWallet.View
{
    public partial class MainMenu : Page
    {
        public static MainMenu link { get; private set; }
        public MainMenu()
        {
            InitializeComponent();
            link = this;
        }
        public string CurrencyConverterChangeCur
        {
            get { return CurrencyConverter.CurrencyConverterLink?.ChangeCur ?? ""; }
        }
    }
}

CurrencyWindow:

<Window x:Class="MyWallet.View.CurrencyWindow"
        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:local="clr-namespace:MyWallet.View"
        mc:Ignorable="d"
        Title="CurrencyWindow" Height="600" Width="500">
    <Grid>
        <StackPanel>
            <ComboBox x:Name="CurrencyComboBox" Text="Выбор валюты" Width="250" Height="35" SelectedIndex="0" FontSize="20" Margin="0 10 0 0">
                <ComboBoxItem Content="Выбор валюты"/>
                <ComboBoxItem Name="BYN">
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="Белорусский рубль"/>
                    </StackPanel>
                </ComboBoxItem>
                <ComboBoxItem Name="USD">
                    <StackPanel Orientation="Horizontal">
                        <TextBlock x:Name="dollarUSA" Text="Доллар США"/>
                    </StackPanel>
                </ComboBoxItem>
                <ComboBoxItem Name="EUR">
                    <StackPanel Orientation="Horizontal">
                        <TextBlock x:Name="euroEUR" Text="Евро"/>
                    </StackPanel>
                </ComboBoxItem>
            </ComboBox>
        </StackPanel>
    </Grid>
</Window>

.cs:

namespace MyWallet.View
{
    public partial class CurrencyWindow : Window
    {
        public CurrencyWindow()
        {
            InitializeComponent();
        }

        public string GetCurrency()
        {
            ComboBoxItem selectedItem = (ComboBoxItem)CurrencyComboBox.SelectedItem;
            string selectedName = selectedItem.Name;
            switch (selectedName) 
            {
                case "USD":
                    return "USD";
                case "BYN":
                    return "BYN";
                case "EUR":
                    return "EUR";
            }
            return "";
        }
    }
}

CurrencyConverter:

<Page x:Class="MyWallet.View.CurrencyConverter"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      xmlns:local="clr-namespace:MyWallet.View"
      mc:Ignorable="d" 
      d:DesignHeight="800" d:DesignWidth="1200"
      Title="CurrencyConverter" Background="#EBFFFF">

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="300"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <Border Grid.Row="0" Background="White">
            <Grid>
                <Border>
                    <TextBlock Text="Валюта по умолчанию: " FontSize="25" VerticalAlignment="Center" Margin="50 0 0 0"/>
                </Border>
                <Border>
                    <Label x:Name="CurrText" Content="BYN" FontSize="25" VerticalAlignment="Center" Margin="330 0 0 0"/>
                </Border>
                <Border>
                    <Button Content="Изменить" Width="250" Height="80" VerticalAlignment="Center" HorizontalAlignment="Right" Margin="0 0 100 0" Click="ChangeCurrencyButton_Click"/>
                </Border>
            </Grid>
        </Border>
    </Grid>
</Page>

.cs:

namespace MyWallet.View
{
    public partial class CurrencyConverter : Page
    {
        public static CurrencyConverter CurrencyConverterLink { get; private set; }
        public CurrencyConverter()
        {
            InitializeComponent();
            CurrencyConverterLink = this;
        }
        private string? changeCur;
        public string? ChangeCur
        {
            get { return changeCur; }
        }
        private void ChangeCurrencyButton_Click(object sender, RoutedEventArgs e)
        {
            CurrencyWindow converterAddWindow = new CurrencyWindow();
            bool? result = converterAddWindow.ShowDialog();

            string oldCurr = CurrText.Content.ToString();

            if (result == false)
            {
                changeCur = converterAddWindow.GetCurrency();
                CurrText.Content = changeCur;

                MainMenu.link.moneyBalance.Content = changeCur; // установил значение moneyBalance
            }
        }
    }
}

MainViewModel:

namespace MyWallet.ViewModel
{
    internal class MainViewModel : ViewModedBase
    {
        private Page MainMenuPage = new MainMenu();
        private Page CurrencyConverterPage = new CurrencyConverter();

        private Page _CurPage = new MainMenu();

        public Page CurPage
        {
            get => _CurPage;
            set => Set(ref _CurPage, value);
        }

        public ICommand OpenMainPage
        {
            get
            {
                return new RelayCommand(()=> CurPage = MainMenuPage);
            }
        }

        public ICommand OpenCurrencyConverterPage
        {
            get
            {
                return new RelayCommand(() => CurPage = CurrencyConverterPage);
            }
        }
    }
}

ViewModelBase:

namespace MyWallet.ViewModel
{
    internal abstract class ViewModedBase : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void onPropertyChanged([CallerMemberName] string PropertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(PropertyName));
        }
        protected virtual bool Set<T>(ref T field, T value, [CallerMemberName] string PropertyName = null)
        {
            if (Equals(field, value)) return false;
            field = value;
            onPropertyChanged(PropertyName);
            return true;
        }
    }
}