the second complilation is still very slow in navmesh buid in worldpartition

I am configuring world partition as 10km * 10km in my project.

I created a navigation mesh from the world partition shared by Unreal.

The navigation build takes about an hour.

my world is not change, when i build the second complilation,

The navigation build still takes about an hour,

is there an option for incremental compilation about th navigation?