NavMeshData doesn't connect for separate prefabs.

I’m making a roguelike game that maps are generated from combining different prefab “map tiles”

So for each prefabs I went on adding them as navigation Statics like the pic above(all those valleys and walls are added).
And after the map is built, I ran the code
to bake them.

But somehow some of the navMeshData do not connect…

How do I fix this? or is there any workaround?

Fixed the problem when I put my buildnavMesh into update call…