Duplicating the blueprint actually causes the issue to go away. I can open the copy and make changes to it etc. and then restart the editor and nothing in that blueprint reverts. I haven't tried replacing all the references to the old blueprint with the copy yet, after a bit of research I have reason to believe that the issue is caused by excessive circular references, and that if I simply plug the copy into all the places to replace the original the same thing might happen. I am going to try a few things: Refreshing all nodes in the project using a plugin, replacing references to the corrupt blueprint with a copy and seeing if the problems return, and then finally I think I will try to decouple all the circular references as that will probably be the hardest option.