Skyatmosphere not working on Apple Silicon under UE5?

Absolute newbie on Mac Studio with M1 Max, fresh install of 5.2.1 and then 5.3 to see if that fixed the problem. I can’t get a skyatmosphere to do anything other than show blue sky. The class I’m following has these instructions from fresh level:

  1. Add directional light, set Atmosphere Sun Light
    2, Add skyatmosphere. Example shows lovely sunset when this is done, which can be varied as the object is moved around.: I just get blue sky, and moving the object does nothing.

So this seems very basic, and googling suggests there might be problems with this since 5.1, so being so new and so early in the class I’m taking, it seems it should work, but other than add a skylight as the documentation suggests, this seems harder than it should be. Has anyone else on Silicon had similar problems?