Question Sleep Tracking Issue

[tmoosetrax]

Just got the Mi Band 4 this week . I've noticed that the sleep tracking does not record when i get up in the middle of the night and takes a while to show that i'm awake and start counting steps in the morning. Could this be due to the heart rate settings i know they offer like 30,10, 5 ,1 minute intervals. Will a lower number help this be more accurate or does it have nothing to do with it, maybe just in need of a firmware update down the road from Xiaomi? Thanks for any advice you may have.