Not sure if anyone else is having this problem but I have a vivoactive 4s and it's suddenly recording my active calories as way lower than usual during a workout. I work out every day and normally burn between 300-400 calories for around 40 mins of cardio (I've had this watch since July and it's been pretty consistent in terms of calories burnt etc). All of a sudden it's now only saying I've burnt around 99 calories for an hour cardio? Definitely inaccurate as my heart rate is reaching around 180 and I'm doing the same amount of effort as usual... unsure why it's suddenly not accurate? I've not changed anything within the app or watch so can't understand a reason for it at all. Any suggestions?