Athena federated query on PostgresSQL

Hi I am trying to execute queries on a postgresql database I created in AWS. I added a data source to Athena, I created the data source for postgresql and I created the lambda function. In lambda function I set:

• default connection string
• spill_bucket and spill prefix (I set the same for both: 'athena-spill'. In the S3 page I cannot see any athena-spill bucket)
• the security group --> I set the security group I created to access the db
• the subnet --> I set one of the database subnet I deployed the lambda function but I received an error and I had to add a new environment variable created with the connection string but named as 'dbname_connection_string'.

After adding this new env variable I am able to see the database in Athena but when I try to execute any query on this database as:

select * from tests_summary limit 10;

I receive this error:

GENERIC_USER_ERROR: Encountered an exception[com.amazonaws.SdkClientException] from your LambdaFunction[arn:aws:lambda:eu-central-1:449809321626:function:data-production-athena-connector-nina-lambda] executed in context[retrieving meta-data] with message[Unable to execute HTTP request: Connect to s3.eu-central-1.amazonaws.com:443 [s3.eu-central-1.amazonaws.com/52.219.170.25] failed: connect timed out]
This query ran against the "public" database, unless qualified by the query. Please post the error message on our forum  or contact customer support  with Query Id: 3366bd80-143e-459c-a4da-5350b5ab4a77

What could be causing the problem?

Thanks a lot!