i assume you're talking about block E3.
the center 2 pattern pieces that come together to form the center pinwheel block should have the corners trimmed down so they line up real nice.
one of the center pieces has both corners clipped and the other piece only has one corner clipped - this makes lining up the 2 sections for perfect point kinda hard.
just lay the 1 piece that has both corners clipped on top of the other piece and clip that long corner down to match the other piece.
then you should be able to line both of those center sections and achieve the perfect points.