Watch has stopped waking on wrist raise
Watch woke on wrist when new less than a year old. This function no longer works.
iPad mini, iOS 9
Check in Control Center, make sure you didn't accidentally activate Theatre Mode.
Check in Settings / Display and Brightness, make sure Wake on Wrist Raise is enabled.
Restart your Apple Watch, a reboot fixes many glitches. Simply press and hold both the Digital Crown and Side Button (together, about 10 seconds) until the Apple logo appears, then release the buttons and let the watch restart.