If you just did an upgrade from 6 to 7, You might find that a factory reset will clear up all the errors. Sometimes things don't install or update correctly causing issues with stuck processes and battery drain / slowness.
Thanks a lot. Tried system UI Tuner settings. But in that only status bar, do not disturb and other icons are appearing. No colour appearance icon found to activate night mode. I did factory resetting now. Let us see whether battery life increases or not.
factory reset and maybe dose is studying ur habits it happens the first week, if u check ur battery u'll see that the android system is drainin more than the screen
Wiping cache does nothing for me a placebo effect like Windows sfc /scannow. Factory reset almost always fixes my issues too like Windows System Restore but unlike Windows Google has a horrible restore system.
Yeah, that's normal, probably last no more than 48 hours, when I first installed NBeta my Nexus6 did it and then later I left Beta, reload Marshmallow and the after ota release for N6, went back into Beta for release and it did it again.