### Elasticsearch Version

8.8.0-SNAPSHOT

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

MacOS

### Problem Description

API when called is returning invalid response, on the same data terms aggs query runs fine 

![image](https://user-images.githubusercontent.com/3505601/220749805-ddf0d735-60d5-4e45-85bf-941ea3076a3f.png)


When run as aggs query 

![image](https://user-images.githubusercontent.com/3505601/220764360-49f7b648-8b15-43cf-afe2-01bd62e8ebc5.png)


### Steps to Reproduce

Queries are mentioned above ^^

### Logs (if relevant)

_No response_
server/src/main/java/org/elasticsearch/index/mapper/flattened/FlattenedFieldMapper.java
} else {
                return new TranslatingTermsEnum(automaton.getTermsEnum(terms));
            }
        }
        @Override
        public BytesRef indexedValueForSearch(Object value) {
            if (value == null) {
                return null;
            }
            String stringValue = value instanceof BytesRef ? ((BytesRef) value).utf8ToString() : value.toString();
            String keyedValue = FlattenedFieldParser.createKeyedValue(key, stringValue);
            return new BytesRef(keyedValue);
        }
        @Override
        public IndexFieldData.Builder fielddataBuilder(FieldDataContext fieldDataContext) {
            failIfNoDocValues();
            return new KeyedFlattenedFieldData.Builder(name(), key, (dv, n) -> new FlattenedDocValuesField(FieldData.toString(dv), n));
        }
        @Override
        public ValueFetcher valueFetcher(SearchExecutionContext context, String format) {
            if (format != null) {
                throw new IllegalArgumentException(
                    "Field [" + rootName + "." + key + "] of type [" + typeName() + "] doesn't support formats."
                );
            }
            return SourceValueFetcher.identity(rootName + "." + key, context, null);
        }
    }
    
    static class TranslatingTermsEnum extends TermsEnum {