When I get a new message in WhatsApp, I get a notification that contains the beginning of the message. After I swipe it away, the old message always returns when I get a new message. How can I prevent those zombie messages from coming back? There is a "mark as read" feature but that is too complicated to use, I have to swipe down and then click, I just want one swipe to completely clear the notification.
The notifications are showed by the Whatsapp (and there is no option in whatsapp to change this). You'll have to request Whatsapp dev for this feature. Personally, I don't think they will consider your request so easily. Anyways, Good Luck!