The server farm account should not be used for other services (SharePoint Server)
APPLIES TO: 
2013 2016 2019 Subscription Edition 
SharePoint in Microsoft 365
Rule Name: The server farm account should not be used for the other services.
Summary: The account that is used to run the SharePoint Server Timer service and other system services in the SharePoint farm should not be used for other services in the farm.
Cause: The farm account, which is used for the SharePoint Server Timer service and the SharePoint Central Administration website, is highly privileged and should not be used for other services on any computers in the server farm. Services in the farm were found to use this account.
Note
You can ignore this event if using the User Profile Synchronization service. The User Profile Synchronization service must run as the farm account in SharePoint Server.
Resolution: Change the account that is used for other services.
Verify that the user account that is performing this procedure is a member of the Farm Administrators group.
In Central Administration , in the Security section, click Configure service accounts.
On the Service Accounts page, in the Credential Management section, in the drop-down list, click the service that you want to update credentials.
In the Select an account for this component list, click the domain account that you want to associate with this service.
If you want to register the account that you selected on the SharePoint Server farm, click Register new managed account.
Click OK.
For more information, see Account permissions and security settings in SharePoint Server 2016 and Account permissions and security settings in SharePoint 2013.