Query elasticseatrch with pyspark and nested fields

Elastic Stack Elasticsearch
1

hello,
I am trying to query with pyspark an index with documents:

{
	"field1": "field1_data",
	"field2": [
	{
		"field2_1": "x1",
		"field2_2": "x2"
	},
	{
		"field2_1": "x3",
		"field2_2": "x4"
	}
	]
}

if i query from kibana:

post my_index/_search
{
	"query": {
		"bool": {
			"must": [],
			"filter": [
				"terms" {
					"field2.field2_1": "x1"
				}
			]
		}
	},
	"_source" = ["field1", "field2.field2_1"]
}

it retruns everyting fine:

hits = 
{
	"field1": "field1_data",
	"field2": [
	{
		"field2_1": "x1"
	}
	]
		
}

now i try to use pyspark:
the data frame schema is:

index1_schema = StructType([
	StructField("field1", StringType(), nullable=True),
	StructField("field2", ArrayType(StructType[
			StructField("field2_1", StringType(), nullable=True),
			StructField("field2_2", StringType(), nullable=True)
		),
		containsNull=False), nullable=True)
])

i create spark options for elastic:

options ={
"es.nodes": ....,
"es.resource": "my_index",
"es.query": '''
{
	"query": {
		"bool": {
			"must": [],
			"filter": [
				"terms" {
					"field2.field2_1": "x1"
				}
			]
		}
	},
	"_source":["field1", "field2.field2_1"]
	}
	'''
]

i create a data frame reader

reader = sparkSession.read.schema(index1_schema).format('org.elasticsearch.spark.sql').options(options)
than i do 

df = reader.load().select(['field1', 'field2']

the df looks like:

field1             |  field2
=======================
"field1_data" | [{Null, Null}]

where field2 contains an array of pyspark rows with one row object :

{
	"field2_1":None
}

what am i doing wrong?
anyone? please help