Note 4 5.1.1 always awake - never sleeps

[Buzz20]

Ever since I updated to lollipop my phone has been draining about 6% on standby and I can barely get through a 8hour work day without it going flat. This is ridiculous. In the past I use to be able to use it the whole day and be like at 50% when I go home.

My brother and my partner also have a note 4 and they are both running 5.1.1 but they do not have this problem at all.
On the battery usage meter, it shows the phone on 100% of the time on my phone but not theirs.

I've sent it back to Samsung twice now, apparently they've replaced the battery circuit board and battery already, reflashed it, clean wipe and its still having the same problem

Has anyone got any advice what I should do next or how to fix it? I'm pretty close to just chucking it away and getting a new phone
Thanks

 

[B. Diddy]

Welcome to Android Central! This probably won't do much, since Samsuing has already done so much with it, but it won't hurt--try a cache partition wipe: https://support.t-mobile.com/docs/DOC-14686

Also, try booting into Safe Mode, to see if the problem stems from a 3rd party app: Galaxy Note 4 Safe Mode: What you need to know | Android Central