Quoted from VidiotGT:
but is there something I should take a look at related to the power into the upper flipper?
No. Two leaf blade switches on the right flipper button. Push in slowly and first lower one fires the lower flipper and then farther in the second one closes and fires the upper flipper.
The same for any pinball with two switches firing two flippers on one side. Leaf blade switches or opto switches.
Nothing wrong with your game.
You can adjust the leaf blades if you want a little quicker. Or push the button all the way in faster.
LTG : )