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 :) 
stack_name = kwargs.get('stack_name', 'stack')
    nested_stack_name = '%s-%s' % (stack_name, common.short_uid())
    stack_params = params.get('Parameters', {})
    stack_params = [{'ParameterKey': k, 'ParameterValue': v} for k, v in stack_params.items()]
    result = {
        'StackName': nested_stack_name,
        'TemplateURL': params.get('TemplateURL'),
        'Parameters': stack_params
    }
    return result
def get_lambda_code_param(params, **kwargs):
    code = params.get('Code', {})
    zip_file = code.get('ZipFile')
    if zip_file and not common.is_base64(zip_file):
        tmp_dir = common.new_tmp_dir()
        handler_file = get_handler_file_from_name(params['Handler'], runtime=params['Runtime'])
        tmp_file = os.path.join(tmp_dir, handler_file)
        common.save_file(tmp_file, zip_file)
        zip_file = create_zip_file(tmp_file, get_content=True)
        code['ZipFile'] = zip_file
        common.rm_rf(tmp_dir)
    return code
def sns_subscription_params(params, **kwargs):