The only thing I can think of is that perhaps your character needs to use Roll instead of Pitch. I don’t know how you have your actor setup for Controller Input, but you can try replacing Add Controller Pitch Input with Add Controller Roll Input. Also change the InputAxis LookUp node to output Axis Value to Make Rot node’s Roll input, instead of Pitch.
If that doesn’t work, I’m afraid I’m all out of ideas without being able to open up your project 