I am not sure why Oktapreview started failing - given the AWS Okta integration was working for past 6 months. This error is generated from Provisioning Tab within Okta Admin console
FAILURE : Failure for account xxxxxxxxx6: The security token included in the request is invalid. (Service: AWSSecurityTokenService; Status Code: 403; Error Code: InvalidClientTokenId; Request ID: fd96569d-d413-4eff-b6b7-743ff1a18a10)
I have already opened a case with Okta. But wanted to see if you may have run into this issue.