It's possible you received a defective replacement Home button. Barring that, you need to [guide|88325|double check] the condition of the flex cable on the button and the condition of the connector on the logic board. You'll also want to closely inspect the components in the area surrounding the connectors as they can sometimes get dislodged when prying the connectors off. If either of these are damaged, it would impede the proper function of the home button.