Macbook is waking up from sleep while on wifi with iMac I have an Macbook Pro 13" 2018 as my portable/home computer and iMac in the office as workstation. When I bring the Macbook to the office and it connects to office wifi, it keeps waking up in the bag, draining the battery.

I tried to reinstall macOS, everything was ok until I signed in with my Apple ID, so I suppose it's due to handoff/continuity (only thing I have installed now is iStat menus and I'm signed to iCloud, nothing else, clean OS.)

I can lose almost full battery in one day in sleep if I don't turn off wifi and also the Macbook gets very hot and it even reboots itself because of the high temperature.



I use macOS 10.15.2 on both computers.

How can I prevent this and still have handoff/continuity enabled?
Power Management is the culprit. 

You should use the pmset command to see what power management has been doing.  In Terminal, the basic command is

pmset -g log


But that gives you all the power management events since last boot time.  You can reduce this with judicious use of grep.  I have used both of these (with similar results):

pmset -g log | grep -e "Wake from" -e "DarkWake" -e "due"
pmset -g log | egrep "\b(Sleep|Wake*|DarkWake|Start)\s{2,}"


Power Management has about 20 settings that can be changed by an admin user.  To view the settings (they will be different when on battery and power):

pmset -g


For my issue, which looks similar to yours, I changed the tcpkeepalive setting.  With this enabled (value = 1), the MacBook will frequently wake up due to network events.  

To change turn off tcpkeepalive use the Terminal command:

sudo pmset -b tcpkeepalive 0


The -b is to set for when running on battery.

I have also tweaked a few other settings like standbydelayhigh, but this is purely tweaking.

This is based on my experience with a MacBook which would lose too much (I thought) battery whilst closed overnight.

You may find these two links helpful:
How to Fix macOS Mojave Battery Draining Issue and 
man pmset.  

Note that I have not changed hibernatemode from the default value of 3.  Many (including the linked article) discuss changing it to 25 which I do not recommend with recent (last 4 years) hardware and macOS version.