How to reproduce:
1. Open attached project.
2. Open "Scene" scene.
3. Bake navmesh. This is the base bake time
4. Enable "clouds" from hierarchy.
5. Bake navmesh. Baking will take insanely long time. (hours/days)
6. Unselect "Navigation static" for clouds.
7. Bake navmesh. Baking time close to base.

Expected: Bake time close to base.
Actual: Baking stuck.

Reproduced on: 5.4.0f3, 5.4.0p2, 5.5.0a6.
Not reproduced on: 5.2.4f1, 5.3.6p3.