I am subscribing to the GatheringNodeData event, I can confirm that the event subscription is successful when the application starts up yet my handler is never called - anyone else had this in 4.9.0?

  public class EventHandlers : ApplicationStartupHandler
  {
    public EventHandlers()
    {
      var searchIndexer = ExamineManager.Instance.IndexProviderCollection["SiteSearchSearcher"];
      searchIndexer.GatheringNodeData += this.SearchIndexerGatheringNodeData;
    }

    private void SearchIndexerGatheringNodeData(object sender, IndexingNodeDataEventArgs e)
    {
      if (e.IndexType == IndexTypes.Content)
      {
        // Extract root node ID from path:
        try
        {
          string rootNodeId = e.Fields["path"].Split(',')[1];
          e.Fields.Add("siteId", rootNodeId);
        }
        catch (Exception ex)
        {
          Log.Add(LogTypes.Error, -1, string.Concat("Failed to add rootNodeId to index: ", ex));
        }
      }
    }