Single resources and compatible groups show the parent resource(s) as part of the ListChild resources section , so that it is possible to navigate to the monitor tab of the parent and to include charts of the parent on the current view.

This is not possible for autogroups.

Go to e.g. a platform with 2 cpus or 2 network adapters or 2 filesystems. Click on the link for one of those in the Left ListChildren section of the monitor tab and you end up with with a list of the individual resources, but without the parent (which is always the same for all resources in an autogroup)