There is a very important caveat in Unity; if the gameobject is deactivated to begin with when you enter the scene, ORK won't be able to recognize that it's there. This means that ORK can't find your deactivated wall.
There's a few ways around this, such as deactivating the wall as you enter the scene, or keeping the wall gameobject active, and instead disabling its mesh renderer and collider, reactivating those components in your event instead.