It looks like this is some kind of a bug. Here's a thread similar to this
https://answers.microsoft.com/en-us/windows/for...
Try reregistering the Spotlight and see if it helps
https://www.elevenforum.com/t/reset-and-re-regi...
(Disclaimer: Elevenforum is a non-Microsoft website but the page provides accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.)
If it doesn't work, you can try using an alternate app to Windows Spotlight, such as this one, which should still give you access to the Bing wallpapers just until Microsoft fixes the issue.