Invitee responses stuck under iOS 8

Upgraded to iOS 8 from 7 this morning. I started getting "invitee responses" which are apparently new notifications in iOS 8. Generally a good feature though I can't seem to control it. Regardless, I'm getting these new notifications when someone accepts or declines meetings, fine. But I have two accepts for a meeting I scheduled prior to the iOS 8 upgrade that won't clear from my "Invitee Responses" in my Calendar inbox. They both are just sitting there with the "OK" button looking like it can be pressed, and when I do nothing happens. Other invite accepts/declines clear when I press "OK" but not these.

How do I clear them? I've restarted the phone, I've double-tapped home and swiped up on Calendar, I've pulled down and refreshed...everything I can think of besides deleting the event (which his recurring and has lots of attendees so I'd rather not).

Ideas?