I've had this unit for about a week, and auto syncing just doesn't seem to be happening. I need to manual sync when I get to get any sleep data, and manual sync again at end of day, or all steps are lost. If you skip a day, it's just gone man....let it go.
Samsung S7 (Android 8.0.0) - Connect app is in the unmonitored apps so power management shouldn't be messing with it.
Vivofit 4 (2.40) - Device set to syn occasionally.
I've removed and re-paired a couple of times, rebooted the phone, not sure what else to try.
So far, this isn't feeling terribly useful. I bought it for motivation, and it's a bummer to lose record of progress.