Are you using an external monitor on the notebook?
To change this behavior, open a terminal and put in
sudo nano /etc/systemd/logind.conf
Arrow Key down to:
#HandleLidSwitch=suspend
Remove the hashtag to allow the system to see the setting and change suspend to ignore:
HandleLidSwitch=ignore
ctrl+x to exit, then y key to say yes to save, then enter key to save the file.
You must log out and in to see the change.
Alternative method for Zorin Core users:
Install gnome tweak tool:
sudo apt install gnome-tweaks
Under the Power setting, toggle the switch do nothing when lid is closed.