elasticsearch not indexing/finding geo_point in a subfield

dev_config.yml

cluster.name: elasticsearch_dev
path.data: ./data/
path.logs: ./log/
network.host: 0.0.0.0

nested-coord.sh

#! /bin/sh

set -e
set -x

index=test$(date +%s)

curl -XPUT http://127.0.0.1:9200/$index -d '{
  "mappings": {
    "doc": {
      "properties": {
        "id": { "type": "string", "index": "not_analyzed" },
        "location.coord": { "type": "geo_point", "lat_lon": true },
        "location2": { "type": "geo_point", "lat_lon": true }
      }
    }
  }
}
'

sleep 1

curl -XPOST http://127.0.0.1:9200/$index/doc/100 -d '
{
  "id": "100",
  "location": {
    "coord": { "lat": 37, "lon": -122 }
  },
  "location2": {"lat": 37, "lon": -122 }
}
'

sleep 1

echo "--- Check that document 100 is there ---"

curl -XGET "http://127.0.0.1:9200/$index/doc/100?pretty=true"

echo "--- Search simple field location2 ---"

curl -XPOST "http://127.0.0.1:9200/$index/doc/_search?pretty=true" -d '
{
  "query": {
    "filtered": {
      "query": { "match_all": {} },
      "filter": {
        "geo_distance": {
          "distance": "20km",
          "location2": { "lat": 37, "lon": -122 }
        }
      }
    }
  }
}
'

echo "--- Search nested field location.coord ---"

curl -XPOST "http://127.0.0.1:9200/$index/doc/_search?pretty=true" -d '
{
  "query": {
    "filtered": {
      "query": { "match_all": {} },
      "filter": {
        "geo_distance": {
          "distance": "20km",
          "location.coord": { "lat": 37, "lon": -122 }
        }
      }
    }
  }
}
'

echo "FYI: curl -XDELETE http://127.0.0.1:9200/$index"