I am doing a smoke collision with a simple object flying through a ‘thin layer’ of smoke but when the sphere SDF hits the surface the collision that is visible is shaped like the bounding box around the SDF. Any ideas on how to solve this?

All suggestions are much appreciated!
Cheers.

Try viewing your collision object. The sphere you show in the image is the mesh, not the SDF. the SDF is often constructed behind the scenes and may have a different shape than the source mesh. (depending upon VDB resolution)