Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi John,
This is a normal behavior. Events added to a group calendar are treated as meetings, and invitations are sent to all subscribed members. When you create an event on a group calendar, it appears as organized by the group. You're automatically added as an attendee, and the event is added to your personal calendar. For more information, you may refer to this article: Schedule a meeting on a group calendar and pay more attention to this paragraphs “Join versus subscribe”.
Regards ,
Rick