Undo broke my graph, Redo Fixed it again.
I pressed Cntl Z after accidentally deleting some links then adding a function afterwards and tried to step back through adding my function and it all broke. (since I have to guess, probably the bit where it tried to remove the input off the function (the step before removing the function itself) around that moment anyway.
Pressed REDO fixing my problem but I thought you should know there is a demon in there somewhere - right around UNDOing the Addition of a function and the subsequent wiring of portals.