Sometimes we need to enter the group in order to assist our staff members. We have not found any other way besides adding ourselves as owners of the group. Because without that we get a "permission denied" message when we try to enter it. Even with Global Admin permissions.
The reason this is a problem is because we get a lot of unwanted emails, calendar items etc.
I made a case with Office 365 support on this and I was told this is by design. Seems like a really bad design. Was hoping there was a reasonable work around for this.