Since it's new, I'd look at the mechanics. Tiny bit of up and down play on the flipper so it doesn't bind on the pawl below ? Too much up and down can be a problem too.
Plunger assembly move freely, pawl isn't binding on plastic link that hooks it to plunger ? Coil stop and front bracket in a straight line and not leaning in or out ?
Then I'd clean the flipper button leaf blade switch. And consider the leaf blade switch for the lower left, might have a crappy connection between the points/contacts riveted to the metal blade. Repean them or replace the leaf blade switch.
LTG : )