Alta sleep information inaccurate

[Aborghetti]

I have a FitBit Alta (not HR) that in the last few weeks is only recording a tiny portion of my sleep. For example last night I slept from 10:40pm until 7:30am and yet the tracker recorded from 1:13am until 3am and that was it.

I have tried resetting the device, making sure it is on tight enough, making sure the handedness is correct and the sleep setting is not on sensitive. I used to get accurate readings so I'm not sure what happened. Is there any other way to fix this? 

Moderator Edit: Clarified subject

[AlejandraFitbit]

It's great to welcome you, @Aborghetti.

Thanks for troubleshooting this sleep issue. If you are having problems with this information, I recommend trying the following:

1. Make sure to not take off your tracker during the night.
2. Do you remember being awake during the night? If yes, that solves it! Keep in mind that your tracker will detect if you are awake and will stop the sleep tracking process. If no, proceed to step three.
3. Restart the tracker. See instructions in the help article: How do I restart my Fitbit device?.
4. Confirm that the tracker is snug on your wrist (with an HR tracker, the lights shouldn't be visible).
5. Try sleeping with the tracker on your non-dominant hand.
6. If the setting was set to sensitive, please switch it to normal. 
7. If steps 1-6 do not solve the issue, I suggest manually editing the sleep log to reflect the time slept. See instructions in the article: How do I edit my sleep history in the Fitbit app?.​

Let me know the outcome.