OK I did some more testing. It works in a new game with all other mods disabled. It works also in a new seablock game with all mods enabled. It doesn't work in any of the saves for my current campaign. I really don't know what that might imply. Is there some way to import a base that might bypass this somehow?
To be specific about 'doesn't work', I see the mod settings, I just get the red highlight around buildings that are more than default distance away, and they are not clickable.