I had same problem. As some other one already said, a projection matrix in camera was wrong. It was generated by using projectionMatrix(for:viewportSize:zNear:zFar:) - https://developer.apple.com/documentation/arkit/arcamera/2923539-projectionmatrix but I set that zFar was too short. After I set zNearz and zFar value properly (e.g. 10.0 meter), I can get some results of hitTest.