I recently got a Vivoactive 4 and I'm having issues with the notifications, the app has all the permissions and is excluded from any battery saving configuration.
I also own a garmin edge 130+ and when it is turned on it receives the notifications but not the watch. I could be using the garmin connect app, viewing the HR from the watch on realtime and the watch doesn't receive notifications.
Other issues that are getting me frustrated is the sleep tracking algorithm, doesn't work very well, doesn't correctly detect the start and end of sleep and today it changed hours after I got up, when I got up it counted about 6:30 hours of sleep, hours later, it changed to 8:40 hours. I also miss the lack of a sleep score.
Previously I was using a Xiaomi watch that I bought for almost 1/3 of the price, with nicer screen, better battery life and none of these issues. I like the garmin integration with my Edge device (this is why I bought a garmin watch) but I might sell this crap and go back to the Xiaomi watch.
The watch is running the latest firmware (7.20), the garmin connect app version is 4.58 running on android 11.