Rather than use the scroll to behaviour use the scroll to position action on every tick and set the position to:
X = lerp(scrollx,player.x,0.5)
Y = lerp(scrolly,player.y,0.5)
this should eliminate any shaking issues you have and give you a smooth camera movement.
You can adjust the speed of the lerp, which will translate to the lag time of the camera move, by adjusting the 0.5 to any number between 0 & 1.