Changing the Desktop background of the current Space does not change the background for other Space(s) When I change the Desktop background in macOS, the change gets reflected only in the current Space and not the others. The background image I am selecting is one from the default set.

I tried disabling use different spaces for displays but that didn't work either.
This is the default behaviour in macOS. If you have more than one Space, the desktop background is changed only for the current Space and not for the others.

Disabling use different spaces for displays have no relation to this behaviour whatsoever.