Stemmer not working [ES 6.7.1]

[Matteo_Pietro_Peru (Matteo Peru)]

Hi everybody, i'have issues using stemmer,
following the guidelines at link
https://www.elastic.co/guide/en/elasticsearch/reference/6.7/mixing-exact-search-with-stemming.html
I created the following index (partial mapping for body limitations)
{
"settings":{
"analysis":{
"analyzer":{
"italian_exact":{
"tokenizer":"standard",
"filter":[
"lowercase"
]
},
"space_analyzer":{
"type":"custom",
"tokenizer":"keyword",
"char_filter":[
],
"filter":[
"whitespace_normalization",
"trim"
]
}
},
"filter":{
"whitespace_normalization":{
"type":"pattern_replace",
"pattern":"\s+",
"replacement":" "
}
}
}
},
"mappings":{
"news":{
"properties":{
"timestamp":{
"type":"date",
"format":"strict_date_optional_time||epoch_millis"
},
"bodyText":{
"type":"text",
"analyzer":"italian",
"fields":{
"exact":{
"type":"text",
"analyzer":"italian_exact"
},
"raw":{
"type":"keyword",
"ignore_above":256
},
"title":{
"type":"text",
"analyzer":"italian",
"fields":{
"exact":{
"type":"text",
"analyzer":"italian_exact"
},
"raw":{
"type":"keyword",
"ignore_above":256
}
}
}
}
}
}
}
}
}
(i'm refreshin' our old queries so I'm trying not to completely deconstruct them) it seems the difference between exact or not don't exists.
{
"size": 100,
"from": 0,
"query": {
"bool": {
"must": {
"query_string": {
"query": "fisco", {/* Or ""fisco"" when i search exact */}
"fields": [
"title"
],
"quote_field_suffix": ".exact"
}
},
"filter": {
"bool": {
"must": [
{
"range": {
"timestamp": {
"lt": "2019-04-08T23:59:59"
}
}
},
{
"term": {
"isFirst": true
}
}
],
"must_not": [
{
"exists": {
"field": "Previgenza"
}
}
]
}
}
}
},
"sort": {
"datejs": {
"order": "desc"
}
},
"highlight": {
"pre_tags": [
"< strong>< em>"
],
"post_tags": [
" "
]
}
}
But the result returned is the same.
I think the error is in the search query, but I could have set the index wrong too...
anyone can help me?
thank you in advance!

[Matteo_Pietro_Peru (Matteo Peru)]

Sorry, it seems the stemmer is working, but seems don't find the root of some words (italian)