Fitbit Sense - Sleep detection issue

[Christ0phe]

Hello

I have got a weird behavior with my Sense 1 device. I set up the watch into sleep mode then when I go back to the main screen with the hour I see the sleep icon for 2 seconds that it goes away. Also my entire sleep is not recorded. The little sleep icon on main screen keeps displaying “-“.

The other weird thing is that when I wake up and start to walk, sometimes I see heartbeat data coming into the little sleep icon.

This is a Sense 1 watch so there is no settings for Sleep like checking the time periods associated to Sleep. But every time I wake up the watch I see the little sleep (moon) icon on top then it goes away after 2 seconds.

What am I doing wrong?
Thank you very much for your support

Christophe

[JohnnyRow]

I think you might misunderstand what 'Sleep Mode' is. It has nothing to do with sleep detection. When you turn sleep mode on, either manually or by a schedule, it does several actions to prevent you from being awakened during your scheduled sleep time, such as preventing notifications and keeping the screen dim.  When you see the moon icon at the top of the screen for 2 seconds, that's a reminder that you still have sleep mode turned on, probably accidentally, and several features, such as turning on watch face with wrist turn, are disabled.
Fitbit doesn't need any setting to know when to detect sleep. It will detect sleep anytime.