Aggregating using sum always yields me zero even when there is a value associated to it

As you can see i can see values in my discover tab.
The problem arises when i try using aggregation trying to sum the value. It is always zero for some reason. The response returned is zero by elasticsearch for the aggregation thus i guess ES search is not able to aggregate it properly for some reason and kibana pics just what ES sends it. is there a way i can make ES pick the sum of values.?

Are the values in the screenshot of the Discover tab of the dcr.ecomm_stargrade_dev-* index?

Yes those are the metrics from thst topic dcr.ecomm_stargrade_dev-*
Also forgot to mention the mapping of all fields are as double.

Issue is resolved . Grok was sending the metric as a string and ES was indexing it as a string even if it was mapped to double . So need to make sure that ES receives the field as a float.