Aggregations do not add up float values

Elastic Stack Elasticsearch
1

Here is what i have in one of my columns

enter image description here

so, all of these values add up to 1.272. Now i tried to create a metric visualization for it but i get

enter image description here

why is it 0? The field is of type number in the index.

Update

So i tried to run this in sense

post indexName/_search
{
  "size": 0,
  "aggs": {
        "sum block": {
          "sum": {
            "field": "blockSize"
          }
        }
      }
    }
  }
}

and i get

{
  "took": 4,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 12,
    "max_score": 0,
    "hits": []
  },
  "aggregations": {
    "sum block": {
      "value": 0
    }
  }
}

why is this happening? Should it not add up the float values? also, in the index mapping

"blockSize": {
            "type": "long"
          }

shouldn't this be float or double? and if it is long, then why does it store a decimal point with the values?