I discovered something interesting about the bizarre background-always-changes-when-switching-virtual-desktops bug. I see that the only desktop that shows the correct background is the active desktop.
There is what the backgrounds should be for all 3 desktops. I am going to try something to see what it does. I attempted to remove “extra” desktops from the Task View from the taskbar before the background was changed. That was unsuccessful due to Windows automatically switching to the desktop that the mouse pointer was over. Here is something that appears to be a workaround for the bug, though (Note to anyone else who has posted about this topic in the past).
1. Remove all additional virtual desktops so that only 1 remains.
2. Change your background (or backgrounds) to whatever you desire it (or them) to be.
3. Add the desired number of virtual desktops back in. (I used the keyboard [Control + Windows + D].)
The background doesn’t (or backgrounds don’t) change when switching virtual desktops. This would suggest to me that the bug might be somehow related to how DeskScapes is handling Windows 11’s virtual desktop function. But, given that I am not a software developer (notably for DeskScapes), I don’t know that. It is simply speculation based on observations and troubleshooting.