1) XD doesn't support scroll triggers, so the act of scroll the screen won't trigger another action, like moving your circle.
2) When you moved the circle when you were in the hover state, you moved the entire component, not the asset. To solve this, create a frame that will bound the motion. This can be a simple rectangle. Just have it be the lower layer. Create the component with the frame and the circle. Then place your circle at the starting position for the normal state. Add the hover state, select the circle and reposition it. Change the component back to the normal state and test it out.