Search by digits doesn't work with edge_ngram

Have a look at what your text is transformed at search time:

POST docs/_analyze
{
  "analyzer": "autocomplete_search",
  "text": [ "123456789й" ]
}
{
  "tokens": [
    {
      "token": "й",
      "start_offset": 9,
      "end_offset": 10,
      "type": "word",
      "position": 0
    }
  ]
}

Have a look at the Doc.