It stops recording by itself

It writes me awake by itself and sometimes doesn’t even recognize I’m sleeping again.

I start manually I’m pretty sure of it and it sometimes write it’s automatic from the beginning.

Here the picture that happened yesterday and today.

Hi, the automatic tracking seems to be the one in the middle (2:58-8:31).
When were you sleeping the last night?
Were the two first attempts (0:32-1:44 and 1:54-2:45) ended manually?
If not, please make sure the app is exluded from all system restrictions on your phone. The tracking needs to be running in the background, so the app must be allowed to run in the background freely. If the manually started tracking is killed by the system, and automatic tracking is enabled, the app will try to start the tracking back automatically, when the system allows it to launch back.

None of them were ended manually (beside the last one 8:35-36), I was sleeping. I had done a check to allow it in background but maybe I’ve to check some other stuff again.

If you toggled the background restrictions in the past, it might have been reverted since. Some phones do this, usually after a major OS update.
If you send the logs (Left ≡ menu → (?) Support → Report a bug), but it does sound like the app is getting killed when in the background.