Nanite Landscapes in Non world partition maps has missing sections

Nanite in non world partition worlds builds with missing section, almost half the landscape is missing.

Looking at the nanite overdraw as attached, it shows an interesting pattern.

Create a non world partition level.
Create a new landscape by importing a heightmap with one of the following resolutions, a pure black texture is fine. (Attached)
2017x2017, 4033x4033, 8129x8129, 2668x2668)
It does not seem to matter what sections / number of components you use, I used the recommended settings from the docs.
Import Landscape
Select Landscape and enable nanite,
Click Build Data