If you have extract class node in graph with some variable connected to another node, and than you decide to rename that variable in your c# script and switch back to unity, the connection of extracted variable will be silently lost!
And if you rename variable back in c# what will not regain the connection and your project will become potentially very silently buggy.
If you access variable directly in graph it will create red orphan connection after renaming it in c#, which gives errors on play to let us know it exists. And if you rename variable back it will be working as expected.
This should be done for extracted variables as well.
Just for the shake of completion for this post, as I’ve replied to you in the Unity forum, this is already fixed as well as many other things and there is even a new Graph Refactor window coming in v3.0 🙂