When receiving Calendar invites, why doesn't it display as a normal Calendar invitation, only meeting.ics?

[iMore Question]

When receiving Calendar invites, does not display as a normal Calendar invitation, omly meeting.ics

When I receive Calendar Invites from my Supervisor, it used to display them correctly. Showing a Date, description and the Accept, Decline, Maybe options. It no longer displays that.

If I send him one, it shows correctly. So is there a setting that's preventing this on my end?

Also, some times it used to automatically insert the invites into my Calendar. How do we do this?

Thanks!

-Matt