Why return error result when use _routing field?

Elastic Stack Elasticsearch
1

Such as url index-0/_search?routing=24320,i search data from 24230 routing,but the result is

"_index": "index-0",
"_type": "member",
"_id": "40865630",
"_score": 1,
"_routing": "22500",

Why 22500 match the search condition?

2

you can use this instead:

POST index/_search
{
  "query": {
    "term": {
      "_routing": {
        "value": "VALUE"
      }
    }
  }
}