Sleep tile freezes the app and Versa stopped tracking sleep since the last update

[Anickoli]

Has anyone noticed issues with your sleep tracker? I have a Fitbit versa and since the last version update I’ve had very odd results with the sleep tracking and my application. 
There have been several nights of sleep that the Fitbit tracks nothing. I’ve made no change in the tightness of the band or anything different that should prevent it from tracking sleep. When I go into theapp and tap on sleep it takes me to the next screen that is purple. the app freezes on this screen every time. I can’t use back button or use any feature on the screen. I have to close the app on iOS and then re-open it. 
I don’t seem to have any other issues except with the sleep function in the app. 

Moderator edit: subject for clarity 

[LiliyaFitbit]

Welcome to the Fitbit Community, @Anickoli.

Thanks for the details shared in your post. I understand your concern and appreciate your efforts. I recommend doing the following:

1. Log out from the Fitbit app.
2. Force quit the Fitbit app.
3. Clear your iOS device's cache: How to Clear Your Browser's Cache on an iPhone.
4. Reboot your iOS device.
5. Open the Fitbit app and log back into your account.

If the issue persists and you're on Apple iOS 12.2 or higher, uninstall and reinstall the Fitbit app. 

Regarding the sleep tracking, I recommend restarting your device and reviewing this article with helpful information about tracking sleep: How do I track my sleep with my Fitbit device? 

Hope this helps!