This can occur if an account is configured within CloudHealth immediately after it was first provisioned on the AWS side. 

In some cases AWS has not yet completed the backend configuration and the initial API call from CloudHealth is rejected by AWS.

To prevent this occurring, it's recommended to introduce a wait/sleep period of several minutes to any scripting/automation of AWS > CHT account provisioning via APIs.

For more information regarding CloudHealth APIs, see:  CloudHealth API Guide