All 737s have a nose-up pitch moment from the thrust of the engines because they're hanging under the wings. The engines of the MAX are more powerful, and posit

All 737s have a nose-up pitch moment from the thrust of the engines because they're hanging under the wings. The engines of the MAX are more powerful, and positioned differently resulting in a stronger nose-up moment. The elevator is not enough to overcome the nose-up pitching moment of the MAX under certain conditions, but the trim is.