When the admin tries to reset the service account password with the steps mentioned in the article - How to reset the password for Email Security.cloud users
However, the service account admin failed to reset the password due to incorrect security questions.
Symantec Email Security.Cloud
Request another service account admin within your organisation to reset the password for the locked-out service account admin or create a support ticket with the Broadcom Support team for assistance in resetting the service account admin password.