Log4net: Filter by a specific property from GlobalContext doesn't seems to be working. How can I set it and use in PropertyFilter correctly?

Question

I'm trying to create a filter in FileAppender that will log just information filtered by 'ApplicationName'. I set the GlobalContext property in main Program and then I tried to use it in the filter block, but it doesn't works. Seems that the GlobalContext property is not being defined.

My Program.cs is liked this:

class Program
{
    private static ILog log;
    static void Main(string[] args)
    {
        string appName = "MyApp";
        log4net.Config.XmlConfigurator.Configure();
        log4net.GlobalContext.Properties["ApplicationName"] = appName;

        log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        log.Info("Info Log!" + appName);
        log.Error("Error Log!" + appName);
        log.Warn("Warn Log!" + appName);
        log.Debug("Debug Log!" + appName);
        log.Fatal("Fatal Log test!" + appName);
        Console.WriteLine("Hit enter");
        Console.ReadLine();
    }
}

And this is my appender in app.config:

<appender name="file" type="log4net.Appender.RollingFileAppender">
  <file value="app.log" />
  <filter type="log4net.Filter.PropertyFilter">
    <Key value="ApplicationName" />
    <StringToMatch value="MyApp" />
  </filter>
  <appendToFile value="true" />
  <rollingStyle value="Size" />
  <maxSizeRollBackups value="5" />
  <maximumFileSize value="10MB" />
  <staticLogFileName value="true" />
  <layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="Date:%date Thread:[%thread] Level:%-5level Logger:%logger - ApplicationName:%P{ApplicationName}; Message:%message%newline" />
  </layout>
</appender>

I also tried to instantiate ILog before setting the GlobalContext variable but I also get the same. Other thing that I tried was to override method FilterDecision to see what is coming in LoggingEvent, and there the Properties is empty.

I just need that this appender filter just by one specific Application.

Thanks!!