Plane is bad because he's hitting on top of the ball. He sorta chops down on it. He has a hard time getting his hands inside and under the ball. I'm not a swing mechanics expert I wouldn't know what to suggest but he's back to a 11 average LA so even though he's top 1/3 in hard hit metrics he's beating it into the ground too often and finding a glove otherwise. Last year he clearly was trying to hit more fly balls with a 16 average launch angle.
Of course the often overlooked thing is he also just takes no walks these days. He's gone from a respectable walk rate to Alexei Ramirez territory in the last couple years. Hitting a lot of ground balls and not taking walks is how you end up with a 50 wRC into late May.