Ugh - similar issue to many here. I replaced the battery, being very careful with the ribbons and re-seating the connections. Everything worked fine - except the haptics. The phone is my son’s. If I use my thumbprint for Touch ID, it doesn’t recognize my thumb and gives the haptic feedback. My son can get in to his phone just fine, but the home button does not give haptic feedback to him. So the haptic engine is working only in the instance of an incorrect touchID or when hitting the volume button. But not otherwise. Everything else works fine…such a weird problem to troubleshoot. We re-seated all the connections and power cycled several times, including the shutting down through the settings menu.