I received the notification in my watch but when I write to respond the message never arrived to the other person, I write normal the message say sent but never arrive
If you sent from the watch, syncronize it with the phone. If you have a line in the watch, check what number is sending the message , the phone line, or the watch line.
This has been an ongoing problem since the last Messenger update. I have reported it to Samsung and Samsung, after examining my logs, said it's a Meta problem. I would suggest doing what I did and to into the app store, locate the Messenger app, choose app details then click on contact developers and report the issue to them.
