Sleep tracking not working after a given time.


This is actually a tough question, tough not in as its complicated to answer but maybe as its going to be more complicated to "understand".

I have a Fenix 6 and a Tactical instinct watch, and i would like to know why in gods name at least in my Fenix 6 if i go to bed after say three or four AM which unfortunately happens the watch just decides not to log any sleep ?

Is this i known limitation ? Im saying this as i cannot see what can be the cause as i have other devices from other brands which also use Firstbeat who not only measure that but also nap times.