Welcome to the Fitbit Community @Vithaya.
Thank you for sharing the issue you're experiencing with your heart rate monitor. I appreciate the information that the green LEDs are flashing and the heart rate setting is set to 'On'. If you haven't done so, I'd like you to restart your tracker as described in this help article. This will refresh your tracker internally. For complete troubleshooting steps, please see this help article: Why don't I see my heart rate on my Fitbit device?
Keep me posted on the outcome!
Want to discuss ways to increase your activity? Visit Get Moving in the Lifestyle Discussion Forum.
Best AnswerI turn heart rate on and restart many time. Turn on and off. Still not working. I think something wrong inside
Best AnswerHi @Vithaya, thank you for your reply.
I really appreciate your efforts to resolve the issue and send pictures. Since the steps you tried didn't work, I've gone ahead and escalated your case to our Support team, for them to take a deeper look at this. Please keep an eye on your inbox for further instructions.
If you have any questions, feel free to let me know.
Want to discuss ways to increase your activity? Visit Get Moving in the Lifestyle Discussion Forum.
Best Answer