What steps will reproduce the problem?
1. Create a recurring series
2. Delete only on of those series.
3.

What is the expected output? What do you see instead?
Well the event should disappear but it does not.

What version of the product are you using? On what operating system?
10.4.10, 2.1

Please provide any additional information below.
I believe the issue lies with loading the data and not emptying it after a
refresh. This would leave certain elements in memory and not remove even
though they are not longer on the xml file.