May be a duplicate of https://github.com/localstack/localstack/issues/988 but due to the age I will re raise.

I'm having issues when I throw an exception in a lambda - it isn't appearing on my dead letter queue. Is there something I am missing, I would like an sqs event exception to appear on the poison queue when an exception happens.

Below is the basic config:
 ````
    sqsclient.create_queue(QueueName = 'test-queue')
    sqsclient.create_queue(QueueName = 'test-queue-poison')

    lambda_client.create_function(
            FunctionName='MyFunction',
            Runtime='dotnetcore2.1',
            Role='role',
            Handler='Handler',
            Code=code,
	    DeadLetterConfig={'TargetArn': 'test-queue-poison-arn'})

     lambda_client.create_event_source_mapping(
		EventSourceArn='test-queue-arn',
		FunctionName='MyFunction',
		Enabled=True,
		BatchSize=100,
		StartingPosition='LATEST')
````

So when I raise a new (.net)exception within the lambda function no message is going to the dead letter queue. I can confirm that all is attached together OK as all other scenarios work, and the above code is pseudo-ish.
@classmethod
    def setUpClass(cls):
        cls.client = aws_stack.connect_to_service('sqs')
    def test_list_queue_tags(self):
        
        
        queue_info = self.client.create_queue(QueueName=TEST_QUEUE_NAME)
        queue_url = queue_info['QueueUrl']
        res = self.client.list_queue_tags(QueueUrl=queue_url)
        
        assert 'Tags' not in res
        
        self.client.delete_queue(QueueUrl=queue_url)
    def test_publish_get_delete_message(self):