You're using the wrong option value. Try UIViewAnimationOptionCurveEaseOut.
UIViewAnimationOptionCurveEaseOut
Replace UIViewAnimationCurveEaseOut into UIViewAnimationOptionCurveEaseOut
UIViewAnimationCurveEaseOut
Eg:
[UIView animateWithDuration:0.4 delay:0.0 UIViewAnimationOptionCurveEaseOut animations:^{ } completion:^(BOOL finished) {}];