I’ve come across a bug when duplicating functions. If you use the duplicate in your BP when you go to compile, it will swap out your duplicate for the original function you made the duplicate from. Doesn’t matter if you rename it or not, or change the internal formula or not. Also even if you save and exit without compiling it will swap them out when you start up the editor again even if you don’t compile.
However creating a new function and using that even if its the same internally and named as your duplicate, works correctly and will not produce the bug. I’m using 4.1.2 so I’m not sure if this exists in the newest version or not. And I’m not sure if that happens or not with all duplicated instances.
Recently one guy asked for swarm missile and I create a function that calculates the intermediate points of a curve between these three points. Then I recognized that I also need two different model of this function for two pints and four points, and I duplicate the first one two times and changed a small step inside them. It worked perfectly fine in UE4 v4.4.1
Either this is a solved issue in newer version or you are doing something wrong. Just try to update you editor version. Not only, it will probably solves your issue, even it provides you new features and many other bug fixes.
I just deleted the duplicates and remade the functions from scratch works fine. It was just something I thought might be worth noting. I’m planning on updating when 4.5 comes out.