I was really scratching my head. Actually, it was more like ripping my hair out in fistfuls! My brand new Inspire 3 was not acting right! The heart rate monitor was working only intermittently at best.
Then it dawned on me, and I switched wrists. At which point it started working perfectly. The difference? The original wrist has a large, dark (black) Celtic knot work tattoo, right where the Inspire 3 was sitting.
The Fitbit heart sensor is an optical sensor, so my tattoo was blocking the passage of light from the green LED.
I just hope I can help others avoid my mistake. Be mindful of tattoos on your wrists!
