Alta HR isn't registering sleep

[AionTempus]

For the past 4 nights this week I've only had full data for one night - two others only provide the basic bar graph with times restless\awake and time spent thus, and one night shows absolutely nothing recorded.

The previous week was fine, but the week before that I had two night with only minimum data, and the two weeks before that each had one night of minimum data.

Why am I encountering all these errors\missing data? Does the device need to be factory reset or something?

I'm trying to monitor my sleep etc for health purposes but if the data isn't provided ... 

Moderator Edit: Clarified subject

[AlejandraFitbit]

It's great to see you around, @AionTempus.

If your tracker isn't registering your sleep information, I recommend trying the following:

1. Manually sync the Fitbit. See instructions in the help article: How do Fitbit devices sync their data?
2. Restart the Fitbit. See instructions in the help article: How do I restart my Fitbit device?
3. Try sleeping with the Fitbit on your non-dominant hand.
4. If steps 1-3 don't work, I suggest manually logging your sleep to reflect the time slept. See instructions in the help article: How do I edit my sleep history in the Fitbit app?

Let me know the outcome.