WPF how to bidirectionally link a checkBox to a class member AND to another static variable

I have a checkbox which is binded to a class variable in the xaml code:

 <CheckBox x:Name="cbxUseBubbleNotifications" Margin="20" IsChecked="{Binding Path=pcdLoggerData.UseBubbleNotifications, Mode=TwoWay}"  Content="_Use bubble notifications"  HorizontalAlignment="Left"  VerticalAlignment="Top" Style="{DynamicResource CheckboxSwitchStyle}" />

this should be supposed to be a two way binding but what happen is:

1. the checkbox is set to CHECKED ----> the var pcdLoggerData.UseBubbleNotifications is automatically OK
2. the class is serialized (through datacontract serialization but I think that doesn't change anything).
3. I restart the program and so the pcdLoggerData.UseBubbleNotifications is automatically set to true 4 the checkbox is not set to TRUE <----- ERROR

point 4 is not correct: since two way I expect to do that automatically.

My class is:

[DataContract]
public class PCDLoggerBinSerializableData
{
  public PCDLoggerBinSerializableData() { }
  public PCDLoggerBinSerializableData(string _languageInUse, bool _useBubbleNotifications)
  {
   LanguageInUse = _languageInUse;
    UseBubbleNotifications = _useBubbleNotifications;
  }
  [DataMember]
  public string LanguageInUse { get; set; }
  [DataMember]
  public bool UseBubbleNotifications { get; set; }
 }
}

Even more important I have to set another variable according to the same value/variations of pcdLogger.UseBubbleNotifications and that is a STATIC var. something like Bubble.NoBubbles = !pcdmisData.UseBubbleNotifications

So two problems:

1. databinding not TWO-WAY working (only one way)
2. how to databind also another static var?

Thanks