Hello Kmartyn5
Just to eliminate one possibility which you did not mention - have you tried deleting the event(s) by touching and holding on the event? This will reveal a delete option. I would also go back to the first of the recurring entries and get rid of the whole sequence.
In Day View you will get a horizontal list with a rightwards arrow for more options which includes Delete.
In Month View tap the List button to see the day’s events then touch and hold on the event. The list button is this icon:
The options shown in your screen shot I think are engaging the invitation process rather than allowing manipulation of the event itself.
Edit - you posted your solution when I was typing my own post. Glad to see you fixed it up.