Bad number display regardless of Mapping used (float, double)

[crpj]

Hello all

After researching and testing I could not figure out why I am still getting wrong numbers returned by queries regardless of the mapping used. E.g. 8.217157748E9

I tried float and double. For the reference, here's a non-aggregated value: 0.3910399955129833

PUT _template/aggregated-template
{
"index_patterns":["aggregated-*"],
"settings": {
"number_of_shards":1
},
"mappings":{
"_source": {
"enabled": true
},
"properties": {
#omitted a few fields here, important ones below
"CALL_COUNT" : {"type" : "integer"},
"CHARGED_USAGE" : {"type" : "double"},
"DATA_VOLUME" : {"type" : "double"},
"AMOUNT" : {"type" : "double"}
}
}
}

#query results
{
"key" : 1570579200000,
"key_as_string" : "20191009",
"doc_count" : 6,
"SUM_CHARGED_USAGE" : {
"value" : 8.193465344020516E9
},
"SUM_CALL_COUNT" : {
"value" : 14.0
},
"SUM_DATA_VOLUME" : {
"value" : 8.217157748E9
},
"SUM_AMOUNT" : {
#OK here, why?
"value" : 432.98415810004917
}
}

Thank you for any guidance.