Please try this and let me know if you experience the same thing. I realize this isn’t a likely use case, but I mistakenly clicked the “trash” button on a single reoccurring event and my calendar has been unstable every since.
1. Create a reoccurring event – Mine is 2nd Saturday of each month until the end of the year.
2. From the screen where you view Events, try to move a single instance of the reoccurring event into the trash by clicking the “Trash” link. Don’t do it from the Edit screen! This will delete all the events, not just the single instance.
3. Go to “Trash” and click “restore” on a single event. When the Active events screen refreshes, you won’t see the events, but if you navigate away and come back. All instances of the deleted event will be restored. These events will be very unstable.
In my experience, editing these events will create duplicates. Delete a single instance will delete all recurrences and so on. I’ve been able to recreate this scenario twice.
Again, not a likely scenario, but it’s an innocent mistake to click the Trash link. I’m sure I’m not the first to do it.