missing terrain when raised?

So i have noticed for a couple years that when i raise the terrain or lower the terrain to a point the ground decides to disappear when i am driving and even when im still in the editor?
i have tried to look this up and all i got was a thread from 3 years go and its the old world editor "no use"
And i know its no mods causing the issue.
so i was wondering if there is a way to stop this in the editor and the game its self?

So the one that shows the large hill is for an example but yes would love to use it in the future
the second one with the floating d-series is the truck on the hill with the camera pointing up.
Now the camera is not going through the ground because the truck is at an angle and my camera is far enough away from the truck to where there is no clipping in the map.