Elasticsearch Dynamic template not working as required

I want to have an elasticsearch schema that has some pre defined fields including an object type field. I want to have all the fields inside that object type field to be string by default.

I have the following mappings and dynamic templates while creating the index.

PUT myindex
{
  "mappings": {
    "doc": {
      "dynamic_templates": [
        {
          "default_string": {
            "path_match": "myObj.*",
            "match_mapping_type": "*",
            "mapping": {
              "type": "text"
            }
          }
        }],
      "properties": {
        "dummy_field_name": { "type": "text" },
        "timestamp": {
          "type": "date",
          "format": "epoch_second"
        },
        "myObj": {
          "type": "object"
        }
      }
    }
  }
}

But when I submit a field inside the object with a numeric value, it is not mapping that field to string.

curl -XPOST "http://elastic-url:8080/myindex/test" -d 
'{"dummy_field_name": "dymmy_value", "myObj":{ "filed_1": 123 , 
"field_2": "some value"}, "timestamp": 1522196333}'

"filed_1" is identified as a number field. But I want it to be stored as a string type.

Field types detected

Can you reverify your mappings ? This works absolutely fine when I tried it locally.
Please paste your mappings after updating a document ?

@Sravanthi_N_S_CH do you see the filed_1 field mapped as a text field and not numeric?

Also what version of elasticsearch are you running? I'm on 5.5.2

@silent_phantom Yes, I could see the field mapped to text.

I am on 5.3

got it to work by using the index level templates
Also, mention "default" as mapping type if you want to apply to all types.