How to remove filled terrain?

I uploaded my terrain file to Cesium Ion, waited for it to process, downloaded the terrain file, and then loaded it using Cesium for Unreal. However, when I load my terrain,but it still fills in other parts of The earth. How can I make it only display my specific terrain?

Cesium ion intentionally gives you a whole globe, because a small patch of terrain floating in space looks strange. As far as I know there is no way to avoid that behavior. I’m curious why it’s a problem for you?