World Partition not unloading pasted assets (UE5-0)

I copied and pasted assets from another map into a blank map with world partition enabled. However, when unloading all of the cells, the assets don’t unload. I made sure “Is Spatially Loaded” was checked for everything.

What step am I missing?

I think I may have solved it, I have to build HLODs from the build menu. However, this ends up crashing UE5 but when I re-load it seems to work properly.