Standard Deviation value is always 0

I have a Elasticsearch datasource setup in Grafana. I’m sending my elastic stack application test results, and have been charting this data in Grafana. I’d like to identify outliers, so I thought Standard Deviation would be a good direction to go. I’m far from statistician, but it seemed to be something that was simple to setup in Grafana. My issue may be how I built my queries, but when I check the standard deviation box, I just get 0. I can see from my test results such as Total test time, that there is some variance on the test results. I feel enough to show deviation. My first query is Average of Total test time. My second query is again for Total field, and Standard Deviation. I assume I’m doing something wrong?

Could you show the query (you can blank out anything sensitive)?

Sure!

xhrStatus:"complete"
request:Object
method:"POST"
url:"api/datasources/proxy/1/_msearch"
data:"{"search_type":"query_then_fetch","ignore_unavailable":true,"index":"filebeat-"} {"size":0,"query":{"bool":{"filter":[{"range":{"@timestamp":{"gte":"1558277434797","lte":"1558363834797","format":"epoch_millis"}}},{"query_string":{"analyze_wildcard":true,"query":"beat.hostname.keyword: TEST-EAST"}}]}},"aggs":{"3":{"date_histogram":{"interval":"5m","field":"@timestamp","min_doc_count":0,"extended_bounds":{"min":"1558277434797","max":"1558363834797"},"format":"epoch_millis"},"aggs":{"10":{"avg":{"field":"Total"}},"12":{"extended_stats":{"field":"Total"}}}}}} "
response:Object
responses:Array[1]
0:Object