In Windows 10, files saved to Desktop show up on the secondary monitor

Whenever I download a file from a browser, or just save a document to the desktop, the icon always shows up on my secondary monitor. Not the primary. So I'm constantly having to minimize windows on my second monitor in order to click & drag the icon to the primary monitor.

In my Google searching of this problem, the only thing I was able to find on it was this one Microsoft Answers page. Anyone got any ideas?

EDIT: Here's 2 screenshots from my display settings. #1 is the primary. It's the one that has all my system tray icons & desktop shortcuts. However, saved files always show up on #2.

I seem to have figured out what was causing the problem. I'm using Stardock Fences (stardock.com/products/fences). After temporarily disabling that, saved docs go to the primary monitor.

I found another possible cause. After right-clicking on desktop->"Display Settings", I scrolled down and noticed that "Multiple displays"->"Make this my main display" box was checked for the wrong monitor. Even though my desktop was shown on the correct display.

Selecting the correct monitor for "Make this my main display" corrected the issue.