https://answers.microsoft.com/zh-hans/windows/forum/all/%E5%BE%AE%E8%BD%AF%E6%8B%BC%E9%9F%B3%E4%B8%AD/b5c8ef9a-3b98-4956-a196-4b1981cfdce5I met exactly the same issue as
Hi,we created many of groups for project or function purpose, now some of projects completed, and the group will not need any more, but we don't want to delete them, is