For enemies in the level to navigate obstacles they need a map
Add a NavigationRegion3D node as a child
Add all nodes that you want to be part of the map
I added the floor and all level objects
Select the NavigationRegion3D Node
In the Inspector add a New NavigationMesh
Now create the map of the level
by hitting the Bake NavigationMesh button
This will now serve as a map of the level for enemies to find their way around