Can someone look at my report output html and explain how things are calculated? Specifically mean for groups.

Gatling (Open-Source)
1

So here is my report:
https://screencast.com/t/VBXxzPANBKjW

here is my gatling config charting section.

charting {
  #noReports = false       # When set to true, don't generate HTML reports
  #maxPlotPerSeries = 1000 # Number of points per graph in Gatling reports
  useGroupDurationMetric = false  # Switch group timings from cumulated response time to group duration.
  indicators {
    #lowerBound = 800      # Lower bound for the requests' response time to track in the reports and the console summary
    #higherBound = 1200    # Higher bound for the requests' response time to track in the reports and the console summary
    #percentile1 = 50      # Value for the 1st percentile to track in the reports, the console summary and Graphite
    #percentile2 = 75      # Value for the 2nd percentile to track in the reports, the console summary and Graphite
    #percentile3 = 95      # Value for the 3rd percentile to track in the reports, the console summary and Graphite
    #percentile4 = 99      # Value for the 4th percentile to track in the reports, the console summary and Graphite
  }
}

The rollups to the group ‘mean column’ do not make sense. At first I thought maybe the group totals are not respecting the groupDurationMetric flag, but changing that flag does not make the numbers line up.

I feel like the group header row has a different dataset they are calculating that what is shown under the group.

What am I missing?