I've had my Venu 3s for 10 days and it won't track my sleep. Everything else seems to be working. I had a Vivosport 5 for 3 years previously and only replaced it because I needed a bigger screen and wanted better tracking now that I am exercising more. It always tracked my sleep fine even when my stress was high.
I've googled extensively, reset and restarted the device, done updates, followed every recommendation. The first night it recorded my sleep, the next night it didn't, the next two nights it started tracking sleep AFTER I first woke up at around 6am. I then reset the device and it tracked properly that night, but then the next night only after I woke up, and since then not at all. It has also recorded a couple of naps that I did not have, which I deleted. I had a very active day yesterday then slept really well with lots of dreaming and woke up to a body battery of 19 and 'no sleep detected'.
I have a pretty regular sleep schedule, and I've been adding manual sleep times in the hope that this might help the device to learn when I am sleeping. I have my sleep times set, and it goes into night mode as scheduled. I'm not getting HRV tracking because it doesn't seem to think I am sleeping, and my body battery goes up and down all night as though I was awake but resting. I don't usually run pulse ox because I would rather have longer battery life, but I tried turning that on to see if it would help the device know when I am sleeping and it doesn't seem to do make any difference either.
I have a pacemaker (I have heart block on one side from surgery, but I set my own rhythm) and I am on beta blockers, but it never caused any problems with my old device and everything else tracks fine. My stress is always in the blue overnight, although does tend to be around 20 most of the time when I am asleep.
I have read that it can take a while for a new device to get to know you, and that the tracking may start working after a few weeks, is this a thing?
I'm getting to the point where I'm ready to return this device and just use the old one even though I can't read the screen any more.