Not receiving notifications

Then you need to explain more about when you are receiving notifications and when you aren't. What do you see on your iPhone? Do you receive notifications on the phone if you are not receiving them on the watch? What troubleshooting have you done on the Watch and phone to try and correct this?

Check this support document to ensure you have Notifications configured correctly between your iPhone and Apple Watch, Notifications on your Apple Watch - Apple Support

Is your phone unlocked?

You will not get notifications on your watch if your iPhone is not locked.