You may need to use an earlier kernel than the current kernel used by Zorin. This method allows you to set the kernel that you will boot into by default.
To set the new kernel to default:
Boot into the kernel you wish to be Saved.
Open terminal and run:
sudo nano /etc/default/grub
Change GRUB_DEFAULT=0 to GRUB_DEFAULT=saved
Hit enter to drop down a line.
Add GRUB_SAVEDEFAULT=true
ctrl+x to exit, then the y key to say yes to save, then the enter key to save as current configuration.
Run
sudo update-grub
to make the changes take effect.
Remember: if you boot into the later kernel for some reason (testing or whatever), that will become the new Saved Kernel at next reboot. So you must hit tab or esc at the M.B. splash screen to get to Advanced Options for Zorin and reselect the preferred kernel and boot into it. Once done, it will then remain as the Saved Default.