Searching multifield with nested object not working in the nested object

[Diogo_Filipe]

Hi,

I'm using Elastic 7.9.2 with ECK 1.2.1. Using Java and Spring too.

I'm trying to query a nested object directly to the id variable(inside the 2nd object) but it always returns zero results.

An example of my mapping, model_objects is the nested object:

"mappings": {
    "properties": {
      "id": {
        "type": "keyword"
      },
      "date": {
        "type": "long"
      },
      "user_id": {
        "type": "keyword"
      }
      "model_objects": {
        "type": "nested",
        "properties": {
          "id": {
            "type": "keyword"
          },
          "name": {
            "type": "keyword",
            "index": false
          }
       }
    }
}

Then this will map to this objects:

public class MessageFromCore {
    private String id;
    private long date;
    private String user_id;
    private List<ModelObjects> model_objects;
}

and

public class ModelObjects {
    private String id;
    private String name;

    public ModelObjects(String id, String name) {
        this.id = id;
        this.name = name;
    }
}

This is indexing and working good for almost everything even search on other parameters except, when I try to search for objects that have a given id to search inside the model_objects, then it always returns an empty response.
The part of the search that is not working is this:

if (messageFromFront.getModel_id() != null) {
   ((BoolQueryBuilder) qb).must(QueryBuilders.termsQuery("model_objects.id", messageFromFront.getModel_id()));
}
//getModel_id() returns a List<String>

This QueryBuilders should work like this according to the documentation or I didn't understand or I'm not seeing something.

I have other QueryBuilders in the same method in other ifs to add to the query and all work together and simultaneously except when I put a model_objects to be searched.

I tried to search for other ways and couldn't find anything that works for me.

Let me know if I need to provide anything else that could help me solve this.
Thank you
Diogo