Go to “Uninstall Applications” and look for Tablet messager.
Do not uninstall, but go to “data” and delete it. Then open Tablet messager. The initial setup is now displayed again.
A menu is displayed during initial setup. You have to scroll down this menu. One of the points is called “Receive messages in the background”. This point must be activated.
In addition, notifications must be allowed in the watch settings and tablet messager must be deactivated under settings- more- backround cleaner- Battery saver.
In addition, the cell phone and the watch also require Internet access. If all these settings have been made AND the devices are connected by scanning the QR code, the reception and writing of whatsapp messages works reliably and without problems.
EDIT you are right, it seems that it’s not working any longer. It was working, even if the screen was off. But I just tryed and I wasn’t able to make it work again.
I will have a look at this.