Can you ensure the Connect app runs in the background? Huawei is famous about killing the processes that are running in the background. If the Connect is stopped, the notifications aren't pushed to the watch. You can read about how to prevent it on dontkillmyapp.com.
They give you an app that is being killed by the system. What should they do? They can add a constant notification, that increases the priority of the process, but they can't deal with every manufacturer's "idea" how to "optimise" battery- and memory usage for you.
I am not Garmin, but can certainly try to help. For speaking to Garmin you'd need to contact them directly, not on this community forum.
Untill now anyone following the troubleshooting guides listed below, managed to fix the notification problems, so I bet it will work for you too, if you read and follow the instructions carefully enough. The user of the last case from today had to enable notifications on the lock-screen in his phone settings, so perhaps you may try checking that too:
I have the same problem, i have a P20 and a Garmin vivoactive 3. When i first got the watch 6 weeks ago, notifications all came through, after a week they stopped. The watch disconnects almost daily and i have to do a reboot of watch / phone or click into the connect app and reconnect. Notifications dont come through at all now, i have tried all of the above, and stil no joy, so frustrating having this amazing watch, and not being able to utilise it to the full.
