I uninstalled (purge) and reinstalled Nemo but I don't think that has any implication on the following because the same observation remains. However, I noticed the copy error isn't uniformly applied. The problem seems to only occur in one type of copy.
Problem: Desktop -> Open folder.
No problem:
Desktop -> Desktop
Open folder -> Desktop
Open folder -> Open folder.
Weird.
I'm going to mark A's last suggestion as solution since all those changes are still in my system and I don't plan to remove them. Pretty sure they helped me to get to this state which I am happy to live with.
I am honestly baffled. I used to use Nemo on Zorin Lite Desktop (Not Cinnamon) and all of the above should have worked. I must be missing something. A step somewhere.
I just tried searching the web but... Not helpful...
We have been researching the issue but haven't been able to find a full fix for it. As XFCE isn't designed to work natively with Nemo, it's unlikely that this issue can be resolved in a reliable manner. Because of this, we would recommend you to continue using the default Thunar file browser in Zorin OS Lite.