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.
try:
            self.conn.create_stream(StreamName=self.stream_name, ShardCount=self.num_shards)
        except Exception as e:
            
            if raise_on_error:
                raise e
    def get_status(self):
        description = self.describe()
        return description.get('StreamStatus')
    def put(self, data, key):
        if not isinstance(data, str):
            data = json.dumps(data)
        return self.conn.put_record(StreamName=self.stream_name, Data=data, PartitionKey=key)
    def read(self, amount=-1, shard='shardId-000000000001'):
        if not self.conn:
            raise Exception('Please create the Kinesis connection first.')
        s_iterator = self.conn.get_shard_iterator(self.stream_name, shard, 'TRIM_HORIZON')
        record = self.conn.get_records(s_iterator['ShardIterator'])
        while True:
            try:
                if record['NextShardIterator'] is None:
                    break
                else:
                    next_entry = self.conn.get_records(record['NextShardIterator'])
                    if len(next_entry['Records']):
                        print(next_entry['Records'][0]['Data'])
                    record = next_entry
            except Exception as e:
                print('Error reading from Kinesis stream "%s": %s' (self.stream_name, e))
    def wait_for(self):