From Butterick 5051. I had to modify the back of the dress; both the halter neck and the lower back were WAY too big. I made the neckline almost three inches shorter to avoid having a neckline down to my bellybutton, and I took in the back center seam two inches because it was gapping open at the armpits.
Maybe the pattern is MUCH larger than others? I made my usual size, which checks out w/my measurements on the pattern envelope.