Wrong.
Place a box instead.
In a cycle the sun rolls all the way around so it will be perpendicular to the terrain too.
Also, the cycle needs to set the light intensity to 0 for night time. It doesn’t solve it all, but it’s a good start.
Add a different light channel exclusive for the moon so it only affects the moon and nothing else.
The box is still required to prevent things - like tree meshes that poke through the landscape - from being lit anyway.
Particularly if using a re-captured Sky light…