Sleep function not working consistently

moi aussi.

My guess is that there is a bug in the interface between the watch and the Connect App (I have an android phone).  Check your sleep calendar in the app and see if there is anything logged during the sleep time.  My app showed the sleep time as awake time.  Then, when I checked Garmin Connect online on my PC, I showed no sleep recorded -- exactly what you say.  The Garmin support "team" (in quotes!) told me they know of no other examples, so I referred them to this and other entries in  their own chat forums.

yes, many back and forth.  The most recent, this morning, from them" 

"Sorry we can't provide a definitive time as to when the issue will be resolved. I thoroughly searched our database when you initially contacted us and we have no current reports of this issue. If time is the essence then exchanging or returning the watch may be necessary. We apologize again for the inconvenience"  

So I referred them to this chat exchange, which apparently they do not check, so they will see that many of us are ahving this problem.

Yes, heart rate, movement and Pulse Ox all very accurate all through the night.  Problem only with properly recording sleep. 

Same issue here. It worked for a few months at the beginning of purchase. Stopped working after a few months. At first I thought it was because I didn't wear the watch long enough during day time. But tried wearing it all day before bed still record nothing. That's why am searching the web for solution and come to here. Will continue searching and see if there's hints. 

It’s now eight months since my original post and it is no better. It’s still spotty. Sometimes it works, others, not at all and some it gives me a few hours. When it only gives me a few hours I add the others manually and then after one or two recalculation cycles it gives me more actual sleep hours. 

My guess is that whatever triggers the sleep recorder and then the algorithm are not working properly.

As to the oxygen, it now doesn’t give me anything in the sleep window, nada, zilch. Whatever the fix if there was any only made things worse.

I find it shocking to see that the Garmin technicians don’t read these comments. 

Garmin support sometimes reads the forums and occasionally comments. However, the only way to guarantee attention to an issue is to open a support call. The more people who report a given problem, the more likely it is to be addressed.

Bump

I too have the the same problem. The only thing I can tell myself is that I didn't buy my fenix 5x for recording sleep. I use it with the heart rate strap and record my sporting activities. It's very annoying though that it's unusable as a sleep tracker even though Garmin claim it's a function of the watch. I won't be buying Garmin again. Garmin should have waited until the technology was good enough to actually put it on a watch.