Yes you are correct a 787 is a flyng Fadaday cage. I also noted horrible phone reception on the ground and i canot recveive GPS while flying like i can in a 777 even over the pole. My google maps works well (if i down load map before flight) showing location, but not on a 787

One advantage if you are like the old brother character in "Better call Saul" no microwave radiation in a 787! Lets not discuss neutrinos!

JJM