HLOD issues (anyway to debug?)

Hi Guys, some possibly dumb questions here, but ive been searching with no luck.
I have a large level (64 sublevels)
I have been trying to build hlods, have generated clusters a-ok, then generated the proxy meshes a-ok, Then build and save the level.

But when i launch the game standalone it says “hlod clusters need rebuilt”
Anyone know what might be wrong? All the meshes seem to be there?!?

Second question, is there a way to debug this from the console?

I’ve been searching this stuff with not much luck, any help appreciated!