Привязка данных к TextBox WPF MVVM с использованием IDataErrorInfo

Написал приложение. Все хорошо работало, свойства во вьюмодель биндил к текстовым полям вью Text

Text= "{Binding PersonName}"

Потом захотел сделать валидацию вводимых данных. Валидация работает, данные из полей в свойства не пишутся.

 <Window.Resources>
    <viewModels:RegistrationFormViewModel x:Key="RegistrationFormViewModel" />
    <converters:BitmapToImageSourceConverter x:Key="BitmapToImageSourceConverter"/>
    <viewModels:RegistrationFormViewModel x:Key="NameInstance" PersonName="" />
    <viewModels:RegistrationFormViewModel x:Key="LastNameInstance" PersonLastName="" />
    <viewModels:RegistrationFormViewModel x:Key="DepartmentInstance" PersonDepartment="" />
    <!-- IData Error style  -->
    <Style x:Key="TextErrorStyle" TargetType="{x:Type TextBox}">
        <Setter Property="Validation.ErrorTemplate">
            <Setter.Value>
                <ControlTemplate x:Name="TextErrorTemplate">
                    <DockPanel>
                        <Border BorderBrush="Red" BorderThickness="2">
                            <AdornedElementPlaceholder/>
                        </Border>
                        <TextBlock FontSize="20" Foreground="Red">*!*</TextBlock>
                    </DockPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <!--<Setter Property="Background" Value="Red"/>-->
                <Setter Property="ToolTip" Value="{Binding RelativeSource={x:Static RelativeSource.Self},Path=(Validation.Errors)[0].ErrorContent}"></Setter>
            </Trigger>
        </Style.Triggers>
    </Style>

</Window.Resources>

Текст бокс

 <TextBox Background="Transparent" BorderBrush="Black" Height="30" Width="140" Style="{StaticResource TextErrorStyle}" 
                              TextAlignment="Center" Foreground="White" HorizontalAlignment="Center">
            <TextBox.Text>
                <Binding Path="PersonName" Source="{StaticResource NameInstance}" ValidatesOnDataErrors="True" UpdateSourceTrigger="PropertyChanged">
                    <Binding.ValidationRules>
                        <ExceptionValidationRule></ExceptionValidationRule>
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
            <TextBox.ToolTip>
                <ToolTip HasDropShadow="True" Content="{Binding EnterPersonName}" />
            </TextBox.ToolTip>
        </TextBox>

Кусок вью модели

public class RegistrationFormViewModel : BaseViewModel, IDataErrorInfo
{
    #region TextBox properties
    /// <summary>
    /// Binding person name to TextBox
    /// </summary>
    [Required(AllowEmptyStrings = false)]
    public string PersonName { get; set; }
    /// <summary>
    /// Binding person last name TextBox
    /// </summary>
    [Required(AllowEmptyStrings = false)]
    public string PersonLastName { get; set; }
    /// <summary>
    /// Binding person department TextBox
    /// </summary>
    [Required(AllowEmptyStrings = false)]
    public string PersonDepartment { get; set; }
    /// <summary>
    /// Error indexer
    /// </summary>
    /// <param name="columnName"></param>
    /// <returns></returns>
    public string this[string columnName]
    {
        get
        {
            string error = String.Empty;
            switch (columnName)
            {
                case "PersonName":
                    if (PersonName == null || PersonName == "")
                    {
                        error = "Введите имя!";
                    }
                    break;
                case "PersonLastName":
                    if (PersonLastName == null || PersonLastName == "")
                    {
                        error = "Введите Фамилию!";
                    }
                    break;
                case "PersonDepartment":
                    if (PersonDepartment == null || PersonDepartment == "")
                    {
                        error = "Введите название отдела!";
                    }
                    break;
            }
            return error;
        }
    }
    /// <summary>
    /// Error exception throwing
    /// </summary>
    public string Error => "Введите данные!";

Базовый класс-наблюдатель

 /// <summary>
/// Class for view notification
/// </summary>
public abstract class NotificationObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
    protected void SetField<T>(ref T field, T value, [CallerMemberName] string propertyName = null)
    {
        if (!EqualityComparer<T>.Default.Equals(field, value))
        {
            field = value;
            OnPropertyChanged(propertyName);
        }
    }
}