Do you use Google now?
No I don't do.
How do you charge phone, original charger?
Depends where I am. Sometimes I use the original charger, sometimes just an USB-cable.
Do you use any bt device?
Yes, I use a Mi Band 2
How is your wifi and mobile signal, because it seem partially your phone is having problem with keeping connection.
My wifi signal is good till strong (at this moment 72 Mbps). I disabled LTE/4G because I do not have always a strong signal.
Your little bit higher battery drain is possibly linked with connection problems and location services(it's not gps). Also your device had some issue with sleep while charging and after. Youll need to check preferred mobile connection settings(4g,3g etc) and apn settings, if you change something in wifi router try to reconfigure or maybe you have poor wifi signal.
Uninstall WhatsApp for now.
Go to wireless settings, advance and disable "scanning allways available".
Go to account settings, other accounts, google and turn off any service synchronization which you dont use abd check for errors there.
Turn off miui backup and log off from xiaomi account.
Go to google settings, location, google location history - delete and disable(very important)
Now put location to "device only"
And now turn location off.
Reboot, leave phone away for a hour atleast.
I need my Xiaomi account for my Mi Band. I followed your instructions and I'll leave my phone away for an hour or more.
Which screenshots do you want to see later tonight?