I am beginning to think it is an issue with Gnome - as Gnome progresses, the more they want to control what you can do - the anti-thesis of GNU/Linux. The cartoon on that link I sent you about DE's sums up Gnome's attitude to Developers and Users alike:
#
There appears to be a big push to minimalise desktops and what you can do with them. That is partly the reason why I prefer KDE over Gnome, but you still get the 60 seconds. There are other suggestions about reducing the time to 10 seconds - guess if it could be reduced to 0 that might solve the issue!
And I don't think it is just related to themes:
Just done a different search and found this possible solution to the 60 second item:
Not sure I understand correctly but there are a lot of different DE's .... desktop environments .... that you can use with Zorin ..... I use Cinnamon which I find is much easier to use and can be customized to your hearts content ..... but I also have Gnome and Xfce all installed but don't really use them .....
You can install KDE by opening a terminal and entering:
sudo apt install kde-full
After installing, reboot and when you click on your user name at the login screen a cog should appear bottom right. Click on that and change from Zorin (default) to KDE (Plasma), then enter your password. After you have chosen KDE you won't have to select again at the next boot. Don't use KMail as anakondi is flaky. You will get an annoying popup KDE Wallet keyring. This can be disabled in privacy settings inside of System Settings.
OK, so you are effectively at a terminal login - enter your username. It will then ask for your account password - note it might not show any dots or asterisks so be careful how you type. Once you have logged in, you should get to your computer name followed by $: indicating you are logged in to the system, albeit with no graphical interface. You can now run sudo commands as required but you may be asked for your password again to elevate you to root. If after login you see #: you are already root.
Once logged in to the system and you want to try and start the graphical interface, enter: