What you need to do is blend the values. If you just have an actor move along the spline, then it’s going to adhere to it directly meaning that there’s no interpolation between the values. You’d have to actually blend from the actor’s current position to the spline position a little ahead of your actor in order to be able to smoothly transition between the points.
Then you would want to blend between the points using either a lerp or a Finterp node.