I have been paying closer attention to this. It feels more like a drag, like the brakes are being applied then there is very subtle bucking before it takes off again as I press the gas. I can tell when its about to happen because it starts to feel like someone is putting on the brakes. it is always up a slight incline.

I just drove it home in sport mode and it seemed to help. I still got the brakes applied feeling but that was it. it never went into bucking mode.