Hi !
The global navmesh was making my editions really slow when I was loading my levels, so after few settings watched in the project’s navs parameters (UE5) I’ve been able to make the same with navmesh inside my sub-level !
More detail about this : In my UE5 (didn’t checked previous versions) there is options to use or not the nav that exist inside loaded levels.
► Because in my project it generate random tile of map, so making an infinite big navmesh wasn’t really possible ^^