because it doesn't fit
It is very close, just a little tight through the upper arm and the waist. Guess I'm up for some reading because I have no idea how to alter this. There are four front pieces, and three back pieces all of which attach to either the pockets or the sleeves, except the center back, and that fits fine. Maybe I should just enlarge the sleeves and the center front pieces at the closure...I have no clue.