Navmesh only reacting to certain collision presets

Hi.

I have created some custom collision presets. When i place an object in the level as Collision Preset A, the Navmesh reacts to it, and removes the area where the object is placed. If i give the object Collision Preset B, nothing happens. Even if i in the editor, set it to the exact same ignore/overlap/block channels as Coll. preset A, nothing happens.
Where can i set the channels that does and doesn’t affect the Navmesh, since it doesn’t seem to have anything to do with the “Modify navmesh” button.

Dont know what caused it. After a restart of the program, the navmesh reads both of the meshes again.