Charge 5 is not tracking my sleep times accurately

[rawlins02]

After recording sleep start fairly accurately for about 8 months, my Charge 5 has started showing sleep start an hour late twice in the past three days. Why would this start to happen? I just changed to sensitive mode after the 2nd error, but I'd like an explanation why the device would quite suddenly become inaccurate with no obvious change in how I sleep, how I wear it, etc. I've seen suggestions for changing time zone in the phone and in the app, but it's not clear why the sudden inaccuracy twice in the past three days.

Also, editing the sleep time to be the correct hour earlier changes the display to show the last hour without any sleep stages other than a few brief wake period, and also shows deep sleep in the first hour, but it does not have that amount in the total deep sleep. Thus it appears that editing sleep start is not a viable option.

Moderator Edit: Clarified subject

[rawlins02]

Update: Looks like the sleep log has updated, so that my edit to sleep start to hour earlier shows first 7 minutes awake and then 46 minute of deep sleep, with the deep sleep total correct, and several stages now appearing in the last hour before awakening. So the edit may have helped the device to "learn" what happened. I'd still like to understand why the sleep start times are occurring later than actual in the past week.

[RiekoC]

Hello @rawlins02 

Every now & then, my Fitbit will not properly track my sleep start time. I've learned to edit the start time in the Fitbit app. As you've seen, it takes some time for the sleep log to update in the app, but it does update.

So far, I haven't been able to figure out what are the factors that result my sleep not being correctly tracked nor have I read any posts that explain why it happens. At least there's a way to correct the sleep log in the app and the tracked sleep information eventually gets updated. 

Perhaps someone else will chime in with some insight.

[rawlins02]

Hello RiekoC,

While some posts have pointed to time zone settings, I also haven't seen any clear answers for this behavior. I'll report anything else I learn.