My Fitbit Sense seems to accurately record heart rate except during exercise. Any other time it matches self measurement or blood pressure cuff. But during exercise, it is significantly off. So much so that I now switch back to my old Versa 2 Lite when I know I will be out exercising to get accurate heart rate measurements. The Versa 2 lite will record heart rates 140-150 while exercising while the Sense is around 100. But if I take a short break, the Sense will instantly find a higher heart rate. As soon as I start up again it goes back to 100. I see several posts about this going back at least two years. Surely there is a fix by now or do I need to file a warranty claim?
