Why I'm getting 0 results when fuzziness is more than 2?

I'm using elastic search 7.6.2

I have index with the following mapping:

        "mappings": {
            "properties": {
                "content": {"type": "text"},
            }
        }

with 3 documents:

  1. michael jordan and scottie pippen - NBA is a professional basketball league in North America.
  2. michael jordan and scottie pippen - National Basketball Association
  3. michael jordan and scottie pippen

I'm running the following simple query:

  "query":{
              "bool":{
                 "must":[
                    {
                       "span_near":{
                          "clauses":[
                             {
                                "span_multi":{
                                   "match":{
                                      "fuzzy":{
                                         "content":{
                                            "value":"hael",
                                            "fuzziness":4
                                         }
                                      }
                                   }
                                }
                             },                           
                          ],
                          "slop":1,
                          "in_order": "true"
                       }
                    }
                 ]
              }
           }
    }

And I'm getting 0 results.

  1. Why I'm not getting results ? (The value hael has 3 missing letters, and the fuzziness is 4) ?
  2. What is the meaning of slop (at the end of the query) ? (It seems that it doesn't do nothing)

The maximum value for fuzziness that Elasticsearch supports is 2. I am surprised it does not return an error indicating this.

It is worth noting that the query you specified witha 4 letter string and fuzziness of 4 would (if there was not a limitation in place) match any word with 4 or less letters as well as a lot of words that are up to 4 characters longer assuming they contain some of the characters in the string. This would return very useful results.