Since the ~last 4 updates, the heart rate reading has been slower than the actual heart rate during any heart rate-raising activity.
For example, during my cardio workout, my heart rate is in the 160-170 range. Yet, when I am looking at my watch it shows 130 or even lower than 100.
It seems the sensor is out of calibration or something.
And if my wrist is a bit sweaty, there isn't reading whatsoever...
It started about 6 months ago give or take.
Did anyone else come across such an issue?