With all due respect, there is an article on How to Reset and Re-register Windows Spotlight in Windows 10.
I occasionally use the link above, and it seems to work for a while before it suddenly gets stuck on the same image again.
However, lately, it has even started to display some nature paintings with rather pale colors, which is another one of its quirks.
I could press Win + L to temporarily lock my desktop-only computer and click "I do NOT like" this and that image to train the feature.
However, I am the only user on my computer, and consequently, I log in automatically, but maybe I should try to do the above.
But honestly, I am a little afraid of locking my computer because I have never, ever done that before, so I might leave it as it is.
Whenever Windows Spotlight is about to show a new image, sometimes it briefly displays a plain dark blue screen (NOT a BSOD).
Good luck!