Done this a few times. Turn the whole grid a bit anti-clockwise, then try to get the right-had side (furthest away from cable connector) seated in properly. While still applying pressure, rotate the grid slowly clockwise, ensuring the groove & ridge mate. As you rotate, the holes will line-up and seat flush. The problem area is the center part near the black circular antenna pod. Very thin groove in grid that needs to seat in very narrow ridge in aluminium body.