I'm using the HRM 600, paired with my Forerunner 970. Everything works fine and all other metrics show similar values as with my HRM tri and from the Forerunner when used without chest strap, except for the step speed loss.
For step speed loss I'm getting values well over 10%, which I confident cannot be true. I do have a slight dent in my sternum, so the strap is not touching my skin in the area around the sensor. Can this be related? Does anyone else experience this issue and maybe found a solution?