It’s easy to create a list of group-enabled SharePoint Online sites using the Get-SPOSite cmdlet. But it’s much more interesting to probe a little deeper to uncover extra information about the group using the GroupId property returned if you specify the Detailed parameter. This post explains a PowerShell script written to examine the possibilities, including how to highlight sites belonging to deleted groups that are kept by retention policies.
https://office365itpros.com/2019/08/15/reporting-group-enabled-sharepoint-online-sites/
