Can you boot into Zorin but hold the Left Shfit key starting at boot to bring up the Recovery Menu.
From the recovery menu, arrow key down to "Enable Networking."
Once that is done, bump back up to the Recovery menu and arrow key down to "Drop to Prompt". Hit enter, then
sudo add-apt-repository -y ppa:yannubuntu/boot-repair
sudo apt install -y boot-repair
boot-repair
Once the process is completed, test by rebooting.