No notifications sound for wechat & whatsapp

If you don't see notifications for a specific app

To get notifications, connect to a Wi-Fi or cellular network. If you still don't get notifications for a specific app, try these steps:

1. Make sure that the app supports notifications. Go to Settings > Notifications, select the app, and make sure that Allow Notifications is on.
2. If you have notifications turned on for an app but you're not receiving alerts, you might not have Banners selected. Go to Settings > Notifications, select the app, then select Banners.
3. Make sure that you’re signed in to your Apple ID. 
4. Make sure that Do Not Disturb is off. 
5. If you’ve recently installed an app or restored it from a backup, open the app to start getting notifications.

Open WhatsApp > Settings > Notifications >

• Message Notifications
• Group Notifications
• In-App Notifications

Check if you have not selected Non of any of the above.

On iPhone

Change alerts

To add or change an alert style for a notification:

1. Go to Settings > Notifications > Check Lock Screen [Ticked]

This has been happening to me as well and in most cases, the message is been shown on the notification but when you open the app: wechat; it will be showing connecting which is very disgusting and have to wait for some seconds later, before i can reply or attend to such message.

this is happening to me as well, no notification for whatsapp and wechat. All these steps i have tried over and over, does not help..i noticed this started after i bought the apple watch