I haven’t tested this specific problem, but from my experience I think this might work. Ok so what I think you should try is to add a BodyVelocity to the ball and set the MaxForce of the BodyVelocity to 0,4000,0, then set the velocity to -y (y is how fast you want the velocity to move down). This should make it continuously move down the y axes but not effect the x or z, which wont effect the rolling of the ball. Again, I haven’t tested this, but I’m PRETTY positive it will work.
Oh, if it’s messing with physics too much, try a BodyForce. The BodyForce basically does the same thing as the BodyVelocity, but it’s still effected by things like gravity and outside forces. Try making a BodyForce and setting the Force to 0, 4000, 0 (This is just an example, if it’s too much pressure, just lower the number) and see how that works.