Yep, my iCloud calendar is there.
As an example, on the iCloud calendar, I have one dinner event for last Saturday. On my Mac I have two of the same event; ditto for my iPhone. On my iPad I have three of the same event!
As suggested in another topic, I turned the devices off and on. The number of dinners remains the same on each device.
I have also used Calendar Cleaner, but it doesn't seem to help in this situation.