Attach a project demonstrating the problem
This project contains the "Photon" and "CBHash" plugins:
https://www.dropbox.com/s/lr9ctu9idlj8qvi/bugUI.capx?dl=0
The steps to follow to reproduce the problem in the project
In the "Photon" plugin, open the "Add event" box and move the mouse up and down on the "On lobby statistics update", "On room list update" and "On room list update" events of the section "Lobby".
In the "CBHash" plugin, open the "Add action" box and do the same on the "SHA-1-password generation" and "SHA-256-password generation" actions.
What you expected to happen
The events and actions mentioned above should not disappear.
What you observed happening instead
The events and actions mentioned above appear and disappear when the mouse passes over them
In these gif you can see how the actions appear and disappear when you move the cursor over them.