Every once and awhile, Windows 11 changes my background, which is supposed to be set to Slideshow of a specific folder, is reverted back to the default background for Windows 11. My computer might be fine for hours to days, but randomly it will revert back. I am using Beta Insider Program (Version 21H2 (OS Build 22000.258), but I have set it so that I leave the program at the next major release. It did happen today, and I did install some updates, but my background was as it should have been when I turned on my computer and didn't revert back for at least 30 minutes.
I'm just looking to report this, but if you know how to fix it let me know.