How to get rotation of an actor, and set the player's rotation to match?

You may have better results either setting the actor rotation (instead of the root scene component) or the camera component. In this case, I set the actor rotation.

Note: Rotation indeed sets to the pawn, but without a camera, the controller doesn’t notice.(using default pawn anyways). Once I added a camera, the rotation of the controlled pawn matched the influencing actor.

Blueprint that controls pawn rotation: