Did fitbit change sleep tracking algorithm recently?

[10thousandsteps]

One reason I love my Fitbit is that it is very accurate in tracking my sleep hours. It can even catch it if I fall asleep during daytime (i.e. while watching TV). However starting from sometime this year it starts to mess up. Now about twice a week, (normally one of the Monday/Tuesdays and Thursday), it only records 1~3 hours. There was a day that it totally missed my sleep. On other days it is able to record correctly (about 6~8 hours).
I have a charge 2 and my wife have a versa (happens to her as well, but less frequently) so I don't think it is a problem of device?
sometimes I wake up at 3 or 4am and then fall asleep again. looks like the failed ones only recorded up to that time and then failed to record the rest. but that isn't always the case.

Moderator edit: subject for clarity

[WilsonFitbit]

Hello @10thousandsteps. Welcome to the community forums. 

Thank you for the detailed information and for the feedback provided. I'd like to let you know that all wrist-based Fitbit devices automatically detect your sleep when you wear your device to bed. I believe there hasn't been any change to the way the Sleep data is being tracked, but for more details, I recommend visiting the following link: How do I track my sleep with my Fitbit device?

On a side note, if you believe your Sleep Data is incorrect, I recommend making some adjustments like changing the Sleep sensitivity setting from Normal to Sensitive or viceversa. Take into consideration that Normal mode is appropriate when you make significant movements like rolling over, so your device records time spent awake. This setting is appropriate for most users. In sensitive mode, your device records nearly all movements as time spent restless or awake. This setting may be helpful if you wake up feeling tired even though your sleep history shows sufficient rest. 

I also recommend performing a restart to your Fitbit device by following the instructions here: How do I restart my Fitbit device?

Hope this helps. 

[10thousandsteps]

Hi Wilson, thanks for the reply. The reason I am bring up this issue is that I have been using fitbit for many years and never had any issue like this until this year, and it happens quite often (about twice a week) and has a pattern (i.e. always Tuesdays and Thursdays). That is why I believe something has changed. Also, I just switched to my wife's device (I bought a new Versa for her) and it still happens, so I don't think it is a problem of device.
One difference that I have noticed is that my fitbit now start doing backend synchronization. i.e., I am at 5000 steps at 6PM and then I go downstairs to play basketball. I don't bring my cell phone with me but when I come back to my room and open my cellphone I can see that it already picked up the new steps. What if it does a background sync at 4AM and then failed to sync the rest of my sleeping later? Just some random thoughts.

[WilsonFitbit]

@10thousandsteps Thank you for your reply. 

If you continue seeing inaccurate sleep or any other discrepancy, my best recommendation is that you please reach out to our Support Team. This way they can further review your situation and further assist. You can contact them through chat or over the phone and you can click here to get connected. 

You can also comment the syncing report to our Support Team, but I'd like to let you know that Data should only automatically syncs to the Fitbit app each time you open the Fitbit app, so your device syncs automatically when it's nearby. If by any chance you're using MobileTrack, I recommend disabling this to avoid any inconvenience with your steps tracked by your Fitbit device and MobileTrack. 

I also recommend visiting the following link, to see how Fitbit devices sync their data: How do Fitbit devices sync their data?. 

See you around. 

[10thousandsteps]

Thanks. but can I still contact support even if my product is no longer under warranty? 

[WilsonFitbit]

@10thousandsteps Thanks for your reply. 

Although your Fitbit device is not within the warranty period, our Support Team can provide additional assistance or troubleshooting steps. If you would like to read our warranty policy, please check: https://www.fitbit.com/global/us/legal/returns-and-warranty. 

In addition, if you reach out to them, please make sure to explain the situation and the troubleshooting steps you've performed, this way they can assist you from there. 

See you around.