I received my Forerunner 935, installed all update but OHR doesn't work for me. I'am black. It worked Well on White people. Crazy! I'm not happy with this product. Do you have the same pb, black people? Thanks
Darker skin (pigment or tattoo) makes it harder for the light to penetrate the skin and reflect back to the sensor. Some companies add another color LED to help with this on darker skin. Scosche for instance adds a yellow LED that is used if the sensor can't lock on a heart rate with the green sensor. If you are not getting a reading on your 935, i'd suggest dealing with Garmin Support. I'm not sure if they have much they can do to help, but they should at least be made aware of the issue. Even if they can't fix the issue in this generation of product, they should include a broader sample of skin tones in their testing going forward.
I find it odd you get no HR at all. That points more to a defective watch to me. I suggest you contact Garmin support and/or where you bought it from to seek a replacement to see if that works any better.
Like I said previously, OHR is working very well on White people (4 different person) and not on black people (3 different person). The Forerunner 735 which was replaced 4 times by Garmin Support worked sometimes :