queryTagHistory aggregation isn't correct

I've searched and have seen several references to issues with both TagCalculations and TagHistory aggregation for minimum and maximum not working. I've created a simple slider to adjust a date/time inspection range that changes the query and an accompanying easy chart to show the data. Something is not making sense. The associated code:

rootpath = event.source.parent.Analog1_UDT.Meta.TagPath
paths = [rootpath + "/ProcessValue"]
endTime = system.date.now()
minutes = -1*event.source.parent.getComponent('Range Slider').value
startTime = system.date.addMinutes(endTime, minutes)
data1 = system.tag.queryTagHistory(paths, startTime, endTime, aggregationMode="Minimum",returnSize=1,ignoreBadQuality=True)
event.source.parent.getComponent('Analog 2 Min Ind').Value = data1.getValueAt(0,1)
data2 = system.tag.queryTagHistory(paths, startTime, endTime, aggregationMode="Average",returnSize=1,ignoreBadQuality=True)
event.source.parent.getComponent('Analog 2 Avg Ind').Value = data2.getValueAt(0,1)
data3 = system.tag.queryTagHistory(paths, startTime, endTime, aggregationMode="Maximum",returnSize=1,ignoreBadQuality=True)
event.source.parent.getComponent('Analog 2 Max Ind').Value = data3.getValueAt(0,1)
event.source.parent.getComponent('Easy Chart').startDate = startTime
event.source.parent.getComponent('Easy Chart').endDate = endTime

If I adjust the chart to show a min/max/min, then the max works.
If I adjust the chart to show a min/max, then the max does not work.

Max is the bottom indicator

Any thoughts?

As a note, you can see that Average changes accordingly, and appears to be correct, even though min and max are both at 200.