When a VCF cloud account within the VCF stack fails data collection with 'System Managed Credentials' enabled, the 'VALIDATE CONNECTION' button reports an 'SDDC Manager credentials are incorrect' error. This specific error combination serves as the indicator that the recovery steps are required.
System managed credentials' checkbox, provide the administrative user credentials for the SDDC Manager. Test the connection to SDDC manager to verify that the provided credentials are valid and and save the adapter configuration.Rotate" next to the 'System managed credentials' to generate a new Service Account in SDDC Manager.System managed credentials' once again and saving the adapter configuration will switch from the user managed credential back to the Service Account.