Hi,
I have a problem when it comes to world partiton.
I already found a thread with the same(?) problem and it may be the same issue here, but I still wonder if this is correct.
What we did so far:
We spawned a lot of test cubes into the scene. Hundreds of actors with instances applied. They were once perfect cubes. Then we computed HLODs and scaled the instances afterward to have a representation when HLODS are loaded and when not.
As you can see, a cross appears in the center of the map. Actually the same behavior that can be seen in the other thread. This is for sure a problem, but as said, when placing assets more carefully and with HLODs, this may may be never a problem.
But what is a problem, the streaming behavior of the individual tiles.
First, the outer part of a tile get loaded. When this is done, the inner part. Even on bigger chunks of the map.
Here is a good example: World Partiton - Loading Issue - YouTube
…and it’s slow. Really slow. What we can see here, are just 30 different cubes, instanced over and over. This shouldn’t be that much of a hassle to load in, right?
Also I do not understand the logic behind what is loaded and what not.
Here, a more reallife example of what I do. The road mesh is splitted into 128m chunks and the tiles close to the player position are loaded. That’s good. The tiles in the back are also loaded - 2km in the distance. That’s not good.
I hope you can help me on this 
Best regards,
Auke