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 :) 
LOG.debug('Validate CloudFormation template: %s' % req_data)
    
    response_content = """
        <Capabilities></Capabilities>
        <CapabilitiesReason></CapabilitiesReason>
        <DeclaredTransforms></DeclaredTransforms>
        <Description></Description>
        <Parameters>
        </Parameters>
    """
    try:
        template_body = get_template_body(req_data)
        template_deployer.template_to_json(template_body)
        response = make_response('ValidateTemplate', response_content)
        return response
    except Exception as err:
        response = error_response('Template Validation Error: %s' % err)
        return response
def transform_template(req_data):
    template_body = get_template_body(req_data)
    parsed = template_deployer.parse_template(template_body)
    policy_map = {
        
        'dummy': 'entry'
        
    }
    class MockPolicyLoader(object):