Thank you, thank you!!! 
I was stuck with this for well over an hour, I was about to give up and go to bed (it’s currently 02h30) but then I saw your post.
Looks like the newer versions of UE need you to explicitly execute the “Create Save Game Object” function, so what I did was add it where Chromarict added the “Save Game To Slot” node after the “Cast Failed” pin and it works!