Double tap to sleep is broken on Nova launcher with beta 12. Probably will be fixed but just a heads up. All normal steps did not work.
Hello @Shrek77 ,
Thank you for the heads-up. As issue involves Nova launcher a 3rd party app, fix needs to be performed from the application side. It would be best if you let them know of issue through their support channels.
One Ui Beta Team
Double tap to lock works for me using the latest Nova Launcher version 7.0.47. I'm on an S21 Ultra and using the accessibility option in settings.