I have CLOSED your other thread.
So from that we understand you have got the AC600 wifi dongle working.
You say there is no settings "cog" against that USB adapter, but there is for the internal wifi adapter.
To be clear, is your remaining issue asking how set the USB as default wifi adapter instead of the internal wifi adapter, without any settings cog for that adapter showing?
From my reading, I see some have solved the issue temporarily by booting an older linux kernel via grub "Additional Options for Zorin".
If you are thinking to get an alternative (linux compliant) USB wifi dongle, maybe this info will help you: USB-WiFi/home/USB_WiFi_Adapters_that_are_supported_with_Linux_in-kernel_drivers.md at main · morrownr/USB-WiFi · GitHub