Make sure, that your "Theatre mode" and "good night mode" is off. Go to "galaxy wearable" app in your phone. Then click on settings. Go in advanced settings and then turn off "Theatre mode" and "good night mode". After that your "wake up gesture should be ON. Now your wake up gesture in galaxy watch will work. Take care.
It's rubbish that I have to turn a feature off in order for another to work.
Samsung galaxy need to fix this wake up issue now. My watch is 4 hours old and I'm already over it.
My watch also had the issue with the wake up gesture not working for my 42mm galaxy-watch. I just completed the latest update for my watch and the wake up gesture is now working...I hope it sticks!
I had the same issue and returned my original watch and got a replacement. With the replacement I left the default watch face.I also turned off the wake-up gesture at night when I sleep and turn it on in the morning. It's been a few days and it seems to be working okay.
Something I did notice when I had the original watch. I would reset the watch and the wake-up gesture would work. Then I would update the Alarm app and the wake-up gesture would start getting buggy. Same thing if I updated the alti-meter app. On the new watch, I removed the Alarm app and the Alti-Meter app. I just reinstalled the Alti-Meter app and it works fine. Not sure if those app updates are causing some type of glitch.