Battery drain after workout

My battery is draining like crazy on my vivoactive 4 after recording a training. I've restarted the watch multiple times after multiple workouts buy it doesn't stop. I suspect it has something to do with the whrm because that's blinking like crazy. 

After training it drains about 1% per 30 mins and restarting doesn't do anything as mentioned in other places in the forum. 

Does anyone know what to do? I've tried to contact Garmin but no response whatsoever, to my email or chat queries!