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.
if delete:
        try:
            
            client.delete_function(FunctionName=func_name)
        except Exception:
            pass
    
    kwargs = {
        'FunctionName': func_name,
        'Runtime': runtime,
        'Handler': handler,
        'Role': LAMBDA_TEST_ROLE,
        'Code': {
            'ZipFile': zip_file
        },
        'Timeout': LAMBDA_DEFAULT_TIMEOUT,
        'Environment': dict(Variables=envvars),
        'Tags': tags
    }
    if layers:
        kwargs['Layers'] = layers
    client.create_function(**kwargs)
    
    if event_source_arn:
        client.create_event_source_mapping(
            FunctionName=func_name,
            EventSourceArn=event_source_arn,
            StartingPosition=starting_position
        )
def assert_objects(asserts, all_objects):