Query in filter Kibana 6 after update not work

[1862347ba9566e72a47d (Tatiana)]

In kibana 5.6, query(filter)

{
  "query": {
    "query_string": {
      "analyze_wildcard": true,
      "fields": [
        "test.keyword"
      ],
      "query": "qwe OR qwerty"
    }
  }
}

work correctly. Shown correct results. After the update Kibana 6, the filter became

{
"query": {
"query_string": {
"analyze_wildcard": true,
"fields": [
"http_host.keyword"
],
"query": "qwe OR qwerty",
"default_field": "*"
}
}
}

Now it does not work, because of the collision of two parameters in query fields and default_field.
It is added by default, re-saving without this parameter does not help.

[Stacey_Gammon]

Looks like this might be a legit issue. I have filed https://github.com/elastic/kibana/issues/15527 for our discovery team to look into.