First, just try making sure the switch opens as soon as the flipper moves at all from its held position. The game can't know the flipper has moved until the switch opens, so if it stays open for the first section of the movement, the game won't react then

go into switch test.. rotate the flipper to full flip position. You'll see the EOS switch light up. Then slowly rotate the flipper back down to see how what your range is on that switch.

beyond that, this will happen naturally as the coils are super strong and with the ball bouncing and the flipper re-hitting on the bounce, you get a dramatic rebound effect.

Reduce the power on the scoop is your only solution.

As FG said that is going to happen on a hard shot to the flippers (on any game). I would make sure the EOS switch is gapped properly and if that's ok then reduce the power on the scoop.