Originally reported in https://github.com/localstack/localstack/issues/2099, the CreationTime for CF stacks was hardcoded. This was fixed in in LocalStack itself (https://github.com/localstack/localstack/pull/2103), but is now also fixed in moto (https://github.com/spulec/moto/pull/2818).

I don't know what version of moto you're using, and whether it's acceptable to use dev-releases, but if you do: 

moto 1.3.15.dev550 should fix this issue, so the LS fix can be removed if you upgrade :) 
def forward_request(self, method, path, data, headers):
        if method == 'OPTIONS':
            return 200
        req_data = None
        if method == 'POST' and path == '/':
            req_data = urlparse.parse_qs(to_str(data))
            req_data = dict([(k, v[0]) for k, v in req_data.items()])
            action = req_data.get('Action')
            stack_name = req_data.get('StackName')
            if action == 'CreateStack':
                event_publisher.fire_event(event_publisher.EVENT_CLOUDFORMATION_CREATE_STACK,
                    payload={'n': event_publisher.get_hash(stack_name)})
            if action == 'DeleteStack':
                client = aws_stack.connect_to_service('cloudformation')
                stack_resources = client.list_stack_resources(StackName=stack_name)['StackResourceSummaries']
                template_deployer.delete_stack(stack_name, stack_resources)
            if action == 'DescribeStackEvents':
                
                run_fix = not stack_name
                if stack_name: