Norton LifeLock: Cannot dismiss an alert

My LifeLock account has an alert that cannot be dismissed 

Are you LifeLock stand-alone plan or Norton 360 with LifeLock plan? 
Are you Norton 360 with Dark Web Monitoring? 

FWIW ~ just guessing:
Maybe, Alert from 2018 is an Historical or Baseline Notification? 

What is a Baseline Notification?

When you enroll, we run a one-time historical dark web scan looking back to 2008 to determine if the information you provided us has been previously exposed. If we find exposed information, we notify you. This is known as a Historical or Baseline Notification.

Why can't I respond to the Dark Web Monitoring Notification to confirm my identity?

For some alerts, we ask you for a confirmation of the activity or transaction so we can determine if there might have been the possibility of an identity theft incident.
For other notifications, such as Dark Web Monitoring, we are notifying you that information which may belong to you has been detected. These notifications do not require confirmation from you because it is a result of a scan we perform on your behalf, and not a result of your activity.

What is the difference between the Exposed Information and the Additional Exposed Information sections within the Dark Web Monitoring Notification?

Your Dark Web Monitoring Notification displays two types of exposed information. When you enroll you provide us information and we monitor it actively. If we detect this information on the Dark Web, it will be displayed in the Exposed Information section of the Dark Web Monitoring Notification.
If we detect other exposed information that may be related to you, we will notify you on this as well. Even if you did not provide the specific information to us, it is possible to use the information you have provided to help detect other information that may have been exposed; but since we have not collected this information from you, we can only notify you that it has been exposed, and not provide any other details. For example, in the case of a healthcare database breach, if you have provided your Insurance Account and Insurance Provider information for monitoring, we may also be able to notify you of additional data that may have been exposed, such as blood type, prescription medications, diagnoses, and related details. This type of information would be displayed in the Additional Exposed Information section of the Dark Web Monitoring Notification.

FAQ: Dark Web Monitoring Notifications
https://support.norton.com/sp/en/us/home/current/solutions/v133398194 

Dark Web Monitoring.
If we find your information on the dark web, we will send you a notification.
We will not remove your information from the dark web and we do not ensure the accuracy or integrity of the information on the dark web.

https://www.nortonlifelock.com/us/en/legal/license-services-agreement/#darkweb

Update your financial accounts, mailing address, and other personal information for Dark Web Monitoring
https://support.norton.com/sp/en/us/home/current/solutions/v126234485

Dark Web Monitoring from LifeLock
https://support.norton.com/sp/en/us/home/current/solutions/v127344370

Get started with LifeLock Identity Theft Protection
https://support.norton.com/sp/en/us/home/current/solutions/v134911435

Maybe try:

LifeLock by Norton Contact Information
QUESTIONS? 1-800-416-0599
https://www.lifelock.com/about/contact/

https://www.lifelock.com/ - 1-800-416-0599 

LifeLock Customer Service - 1-800-LifeLock - 1 (800) 543-3562
LifeLock Identity Theft Protection services - 855-993-1976
Cybersecurity department for Lifelock - 800-745-6061

Is a credit freeze or fraud alert right for you?
https://www.consumer.ftc.gov/blog/2022/02/credit-freeze-or-fraud-alert-right-you

Caveat: I do not have LifeLock plan nor Norton 360 with LifeLock plan -