This issue already exists but is marked as Cannot Reproduce, however it is easily reproducible in a blank project in 4.15 (or 4.13 where it was attempted in the bug).
[Unreal Engine Issues and Bug Tracker (UE-27317)][1]
The steps to reproduce are exactly the same as described in the issue.
Bind To nodes will correctly update, but the event nodes added with the + will break with no error message or warning. The fact that it breaks silently is pretty bad.
