Outlook 2016 Mac: Can't accept meeting invitations for which organizer has not requested a response

In Outlook 2016 for Mac, whenever I receive a meeting invitation for which the organizer has not requested a response, I can't do anything with it at all. In Windows, I can accept, tentatively accept, or decline it (which doesn't send a response) but on my Mac it just sits there in my mailbox unless I delete it. My calendar then shows the meeting as shaded, which indicates that I haven't done anything to acknowledge it, and if I open it from the calendar, I can do all the above, including with sending a response.

Please fix this.