1. Create a project, make it use world composition
2. Create a persistent map with a NavmeshBoundsVolume
3. Make it build of sublevels containing NavmeshBoundsVolumes of their own
4. Configure project to use static navmesh generation
5. Build navigation, test it in PIE
6. Relunch the editor, load a map
Result: navmesh is not being drawn (as if it was missing)
Expected: works as expected
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-27362 in the post.