App not recording data

Detailed description of the problem:
Sometimes it works and records sleep data perfectly, other times it just doesn’t, its random.
I am using a Tickwatch E with Wear OS, everything connected, updated to the latest version.
Using Android 8.1.0

So basically i connect it everyday to record sleep data. Once i click the sleep button on the phone app i immediately open the sleep app on the watch ( if its not done at the same exact time it just doesn’t connect at all ).
Then it says on the phone app “Wearables connected” and the “Check” icon flashes on the watch ( meaning it is connected and recording ).

And then i wake up in the morning to find out either a fully recorded night with the corresponding graphic, or a completely blank empty graphic with no single record.

So basically it randomly just doesn’t record at all, even though it says it is connected and the “Check” flashes. Worst of all it doesn’t do anything different when it doesn’t record, the steps are all exactly the same, and nothing changes or even gives any sign that something is not right.

Version of Sleep as Android:

Same here!
Since I started to use Xiaomi Mi band 4, sleep started to registry no data some nights. I use the Mi band 4 and sonar sensor to sleep tracking.
Sleep version: 20191101.