Vector blur node and the fisheye camera

Hello everyone,

I’m new to Blender and I’m working on the scene with the fisheye camera. My fisheye camera consists of the orthographic camera and the spherical mirror before the camera (for 180° fields of view). I have problem with the vector blur node in the node editor - the vector blur doesn’t work when I use reflection on the spherical mirror (without spherical mirror the vector blur works…). How can I get the vector blur effect on the spherical mirror?

Thanks!