Is there a setting for this?
You've taught me something new today
There is an option if you download dconf from the software store
Then navigate to:
/org/gnome/desktop/peripherals/touchpad/send-events
Within that you will see a default value that if you turn off you can select a custom value, with one of them being "disabled-on-external-mouse"
Give it a test and let me know how it goes. Hopefully this works out for you.
EDIT to say: If you are running zorin core and not lite*
Hi. OS is 17.2 Core. That worked! Question: that path that I drilled down to in dconf... what would be the equivalent were I to edit via command line? For example... /org does not exist. Thanks again!!
So it's not a physical location, it's for gsettings. For example, if you wanted to find the value of a setting:
gsettings get org.gnome.desktop.peripherals.touchpad send-events
This would return what value was set on your system, for my instance, it would be 'enabled'
You could similarly use it to "set" a setting as well, such as:
gsettings set org.gnome.desktop.peripherals.touchpad send-events disabled
That would set the setting you just changed, but through the terminal. Dconf is a "pretty" ui for the low level settings the Gnome believes maybe you shouldn't touch without knowing what you're doing. As if that would stop anyone from doing so
I'll leave a little link to a bit more information, but there's quite a bit you can do, so feel free to find out more in some free time you have. For now, I'll mark my previous answer as solved since you say this has fixed your problem
https://manpages.ubuntu.com/manpages/mantic/man1/gsettings.1.html
When you have time, can you modify your forum profile to state edition of ZoinOS is "Core". That will help us help you in the future.