Landscape Gets Darker When I Lower It

So When i lower My landscape it is darker and wet looking I’ve checked everything

Shadows, Landscape Material, Level Blueprint, World Settings,

And I’ve looked on the island to see if it’s normal but it’s not?

I need to lower the landscape to fix my water for my map I’m using Valguero settings

here’s a screenshot of the issue. I had to crop the image to put in here

Before I Lower The Landscape

After I Lower The Landscape

I’m wondering if anyone else has this issue and knows how to fix it thank you