How does ALandscape::LandscapeComponents work with World Partition?

What worked for me to get those components is to delete the default landscape. and create a new one. could’ve been version upgrade from 5.3.0 to 5.3.1 not sure. but now I have the components.

Is now crashing for me on calling this code:

Landscape->LandscapeComponents[0]->SetHeightmap(HeightMap);
Landscape->LandscapeComponents[0]->RequestHeightmapUpdate();

texture size was incorrect at first, now its showing an error with streaming proxy something. can’t figure out whats wrong.