The SharePoint Online admin center displays an insight card for the number of unlabeled sites in the tenant. For some reason, many of the labels assigned to Microsoft 365 Groups and Teams had not reached SharePoint. Some PowerShell does the job to fetch the sensitivity label information from Exchange Online and update sites with the missing label information.
https://office365itpros.com/2021/11/11/update-sharepoint-online-sites-sensitivity-labels/
