I have a heart rate reporting issue while sleeping with my GWA2. I also have a Garmin Vivoactive 3 watch and when I wear both of them while sleeping, Garmin reports the sleeping heart beat accurately which is about 50-55. But GWA2 reports it about 35-40. There is definitely something wrong with the sleeping heart rate reporting. I guess that's why the watch's stress reporting is limited to the day time.
