Hello.
It is since 3 days I'm losing my mind...
I reported this to Unity too.
That's weird indeed.
I'm making a boss fight, ok?
At a certain point, when I edited the map to try it in a new level design context, it stopped working.
After I modeled the map, I set new static meshes, so I needed to rebuild\bake the navmesh... the result is a failure: now the AI doesn't follow the player anymore, and I made just ONE bake.
Some help?