Hi Jamie,
Sorry for the delay on getting back to you on this. I’d like to have you try deleting and recreating some of the problem recurring events if it’s not too much trouble. If that doesn’t work try exporting your events via the WordPress exporter, deleting them and then re-importing. When I did this with your events, I did not have the duplicating issue.
Let me know how that goes.
Thanks,
Jonah