Hmm I tried looking through all my blueprints, there’s nothing that stores variables from the previous level specifically but I do reference the game instance to record things like health between levels etc.
I did try what @EliasWick suggested and changed the node from Open Level (by Object Reference) to Open Level (by Name) and it’s working again but I still don’t like that I don’t know why the former method wasn’t working 
I’m not 100% sure I understand your proposed solution - are you suggesting I append the world soft object variable before it gets plugged into the Open Level (by Object Reference) node?
Sorry, I really appreciate the help!