AWS Config Rule 'iam-user-unused-credentials-check' Not Evaluating

Hi,

I've configured the 'iam-user-unused-credentials-check' rule in AWS Config but it doesn't seem to be evaluating. It has been a few days and there are no compliant or non-compliant results. Are there any requirements for this rule to work (such as AWS Config recording enabled or AWS CloudTrail enabled)? Other rules seem to be evaluating (s3-bucket-public-read-prohibited and vpc-sg-open-only-to-authorized-ports).

Thanks for any input.