gnome – How to configure copy vs. move when draging and droping between volumes?

I installed 20.04, did the updates, and ran sudo apt-get install gnome-session-flashback. Then I did the updates again.

The issue I have now is when I drag an item from one volume (USB flash stick) to another volume (Desktop), the file will move, instead of copy (unless I press ‘CTRL’, then it will copy). However, when I drag and drop in the opposite direction (from Desktop to USB stick), the files will copy.

How do I configure copying across volumes (instead of moving) without having to press the ‘CTRL’ button?