Strange navmesh behaviour in large tiled world

I have a huge map with 256 2x2km tiles. I have one giant navmesh bounds volume in the persistant level that covers all 1024 square km. It is set to only generate around navigation invokers. It is a solid system when it works. The problem is when I package the game the navmesh is not generating at all.

I noticed that when I first load the map and try to play in the editor it also doesn’t work until I move the world origin closer to the place the player starts So I guess its got something to do with the world origin but what?

After a lot of searching I found the console command RebuildNavigation

Putting EventBeginPlay > RebuildNavigation on my persistent level blueprint did the trick.

No idea why but it works haha.