title: RadioButton Not Checked on Start
body: <p>I have an application with four radio buttons to select the mode I am operating.
  All the 4 Radio Buttons are binded to the same property. When i start the program the none of the radio button is checked.</p>
  
  <p>This is the code for the radio buttons:</p>
  
  <pre><code>    &lt;GroupBox Grid.Row="0" Margin="10,10,10,10" FontSize="16" 
      FontWeight="Bold"&gt;
          &lt;GroupBox.Header&gt;Tipo di Rientro&lt;/GroupBox.Header&gt;
          &lt;StackPanel&gt;
              &lt;RadioButton Name="RdBtnExternalEntry" FontSize="12" 
              FontWeight="Normal" GroupName="SelectionType" IsChecked="{Binding 
              Path=CurrentOption, Mode=TwoWay, Converter={StaticResource 
              enumConverter}, ConverterParameter=ExternalEntry}"&gt;Entrata da 
              Esterno&lt;/RadioButton&gt;
  
              &lt;RadioButton Name="RdBtnEntryAfterCheck" FontSize="12" 
              FontWeight="Normal" GroupName="SelectionType" IsChecked="{Binding 
              Path=CurrentOption, Mode=TwoWay, Converter={StaticResource 
              enumConverter}, ConverterParameter=EntryAfterCheck}"&gt;Rientro dopo 
              visione&lt;/RadioButton&gt;
  
              &lt;RadioButton Name="RdBtnEntryMissingShipping" FontSize="12" 
              FontWeight="Normal" GroupName="SelectionType" IsChecked="{Binding 
              Path=CurrentOption, Mode=TwoWay, Converter={StaticResource 
              enumConverter}, ConverterParameter=EntryMissingShipping}"&gt;Rientro 
              per mancata Spedizione&lt;/RadioButton&gt;
  
              &lt;RadioButton Name="RdBtnEntryAfterPicking" FontSize="12" 
              FontWeight="Normal" GroupName="SelectionType" IsChecked="{Binding 
              Path=CurrentOption, Mode=TwoWay, Converter={StaticResource 
              enumConverter}, ConverterParameter=EntryAfterPicking}"&gt;Rientro 
              dopo Picking&lt;/RadioButton&gt;
          &lt;/StackPanel&gt;
      &lt;/GroupBox&gt;
  </code></pre>
  
  <p>This is the property:</p>
  
  <pre><code>public RadioOptions CurrentOption
          {
              get =&gt; _currentOption;
              set
              {
                  _currentOption = value;
                  NewLoadCommand.RaiseCanExecuteChanged();
                  ConfirmCommand.RaiseCanExecuteChanged();
                  if (value == RadioOptions.ExternalEntry)
                  {
                      _selectedStockUnitCode = PalletToDo;
                      SelectedLoadnumber = LoadToDo;
                      RaisePropertyChanged("SelectedLoadnumber");
                      RaisePropertyChanged("SelectedStockUnitCode");
                  }
                  else
                  {
                      SelectedLoadnumber = "0";
                      RaisePropertyChanged("SelectedLoadnumber");
                  }
  
                  RaisePropertyChanged("SelectedStockUnitCodeIsEnabled");
                  RaisePropertyChanged("SelectedLoadnumberIsEnabled");
              }
          }
  </code></pre>
  
  <p>And this is the converter:</p>
  
  <pre><code>public class EnumMatchToBooleanConverter : IValueConverter
      {
          public object Convert(object value, Type targetType,
                                object parameter, CultureInfo culture)
          {
              if (value == null || parameter == null)
                  return false;
  
              string checkValue = value.ToString();
              string targetValue = parameter.ToString();
              return checkValue.Equals(targetValue,
                       StringComparison.InvariantCultureIgnoreCase);
          }
  
          public object ConvertBack(object value, Type targetType,
                                    object parameter, CultureInfo culture)
          {
              if (value == null || parameter == null)
                  return null;
  
              bool useValue = (bool)value;
              string targetValue = parameter.ToString();
              if (useValue)
                  return Enum.Parse(targetType, targetValue);
  
              return Binding.DoNothing;
          }
  
      }
  </code></pre>
  
  <p>these are the radio options:</p>
  
  <pre><code>public enum RadioOptions { ExternalEntry, EntryAfterCheck, EntryMissingShipping, EntryAfterPicking }
  </code></pre>
  
  <p>I expect the first combobox to be checked at the start of the program</p>