Apple Watch isn’t working on wrist raise. Theatre mode is not on.
Apple Watch is not waking up when wrist is raised. Theatre mode is not on. Any other fixes?
Apple Watch Series 6, watchOS 10
Question marked as
Open the Settings app 
on your Apple Watch, go to Display & Brightness, then turn on Wake on Wrist Raise and Wake On Crown Rotation.
If your Apple Watch doesn’t wake when you raise your wrist, make sure you selected the proper wrist and watch orientation. If your Apple Watch doesn’t wake when you tap the display or press or turn the Digital Crown, it may need charging.
For more info, see the "Wake the Apple Watch display section in:
Turn on and wake Apple Watch - Apple Support