What about Wake screen is not working? Are you looking on the Watch, or in the Watch app on the iPhone? The Wake settings in the Watch app on the iPhone should be located in Settings>Display & Brightness>Wake on Wrist Raise. Also, if the screen is remaining black, it is possible that Theater Mode has been activated. Swipe up from the bottom of the Watch screen to bring up Control Center. Find the icon with the 2 theater masks. If it is white, it is off, if yellow it is turned on. If you turn it off, the Watch should be back to normal.