DynamoDB Stream Event Source for Java & Python lambda behaves differently with partial failures

Hi thanks for being interested in my question. Here are my code: Python:

import json

def handler(event, context):
    records = event.get("Records")
    curRecordSequenceNumber = "";
    
    for record in records:
        curRecordSequenceNumber = record["dynamodb"]["SequenceNumber"]
        print({"batchItemFailures":[{"itemIdentifier": curRecordSequenceNumber}]})
        return {"batchItemFailures":[{"itemIdentifier": curRecordSequenceNumber}]}

    return {"batchItemFailures":[]}

Java:

... // Some import

public class TestStreamHandler implements RequestHandler<DynamodbEvent, Serializable> {
    LambdaLogger logger;
    final static ObjectMapper objectMapper = new ObjectMapper();

    @Override
    public StreamsEventResponse handleRequest(DynamodbEvent input, Context context) {
        logger = context.getLogger();
        List<StreamsEventResponse.BatchItemFailure> batchItemFailures = new ArrayList<>();
        String curRecordSequenceNumber = "";

        for (DynamodbEvent.DynamodbStreamRecord dynamodbStreamRecord : input.getRecords()) {
            StreamRecord dynamodbRecord = dynamodbStreamRecord.getDynamodb();
            curRecordSequenceNumber = dynamodbRecord.getSequenceNumber();

            batchItemFailures.add(new StreamsEventResponse.BatchItemFailure(curRecordSequenceNumber));
            return new StreamsEventResponse(batchItemFailures);
        }
        return new StreamsEventResponse();
}

Here is my event configuration:

DynamoDB: TestStreamTable
arn:aws:dynamodb:ap-southeast-1:<myaccount>:table/TestStreamTable/stream/2023-11-18T15:42:39.936
state: Enabled
Details
Activate trigger: Yes
Batch size: 100
Batch window: None
Concurrent batches per shard: 1
Last processing result: OK
Maximum age of record: -1
On-failure destination: arn:aws:sqs:ap-southeast-1:<myaccount>:TestStreamFuncPythonSQS
Report batch item failures: Yes
Retry attempts: 2
Split batch on error: Yes
Starting position: TRIM_HORIZON
Tumbling window duration: None
UUID: <id>

And for Java:

DynamoDB: TestStreamTable
arn:aws:dynamodb:ap-southeast-1:<myaccount>:table/TestStreamTable/stream/2023-11-18T15:42:39.936
state: Enabled
Details
Activate trigger: Yes
Batch size: 100
Batch window: None
Concurrent batches per shard: 1
Last processing result: OK
Maximum age of record: -1
On-failure destination: arn:aws:sqs:ap-southeast-1:<myaccount>:TestStreamFuncJavaSQS
Report batch item failures: Yes
Retry attempts: 2
Split batch on error: Yes
Starting position: TRIM_HORIZON
Tumbling window duration: None
UUID: <id>

Could you help to have a look?