O365 Group Calendar Event Attachment not visible for Invited Users/Groups

When creating an event in a group calendar and attaching a file to it, the attendees do not see the file in their copied event.

1. Group A creates an Event "Test Event" in the Group Calendar and attaches a .txt file.
2. Group B is invited to that Event.
3. Group B does not see the attachment in the event that was copied to Group Bs calendar.
4. Also attachment is not visible in the Personal Calendars of the Members of Group B. (where it gets copied because they subscribe to Group B)

Why does the attachment not show up?

It only shows up in Group As calendar.