Very large plane created with Blender can't get right Collisions

I’m trying to make a “Round” world. I say “Round” because the way I did this is by making a sphere in Blender comprised of 128 faces, then divide each one of those faces to treat them as terrains. There’s a zone that’s almost a perfect square, which I chose to do a prototype for gaming capabilities, I’ll call this terrain Zone 69 from here on.

I scaled zone 69 to x: 10000 y: 10000 z:10000 inside Blender, then imported it to Unreal.

My problem is: The Mesh Collider is so big, the character is left hovering over zone 69 always, instead of walking over the plane itself.

I’ve tried to do Convex Decomposition to the max values in order to make a Collider with the same shape as zone 69 and to make simplex collision as complex collision. Nothing worked.

Here’s a picture of a Wireframe of Zone 69 (Purple Line) Along with it’s collider (Black Line):

And a picture of the character hovering:

If auto creation of collision does not work well in UE4 I usually create the collsions in Blender:

Select the mesh in Blender, make a duplicate and hide the original. If you have a complex mesh then cut your mesh copy with a knife into smaller parts. Select the parts of the mesh. Hit “Space” to open search in Edit mode of Blender. Enter “Convex” to create a convex mesh from your selection. Seperate the part of the mesh with “P” (and delete it from your copy so you know which parts are missing if you split/knife or whatever your original). Afterwards name the convex block to UCX_whatever_01… then select the next part of your mesh-copy… make convex block again, seperate again, name it UCX_whatever_02 and so on until no part of your copy remains. Finally select everything and apply scale (to avoid scaling issues in UE4), export in Blender (your mesh and all those UCX meshes together in one export) and import it with the collisions in UE4. UE4 would use the UCX (convex) or UBX (box) blocks afterwards. This usually works if auto-creation of collision does not work in UE4.