Rogue Event that can't be deleted

Rogue Event that can't be deleted

I have several "rogue" events that started off as recurring from my zCRM calendar.
I then deleted the recurring event from my zCRM calendar.
The "rogue" events still show in my calendar.zoho.com calendar and cannot be edited or deleted.
How do i get rid of these "rogue" entries and get my calendar cleaned up?

Thanks in advance for all of your hard work!