Halo doesn't appear fully when there is a background image

Hi I have a problem with Halo not appearing fully when there is a background image added to the scene. I am creating a 2D game with a background image sprite. Upon collision/trigger with a gameobject a Halo should appear but all I get is a color change on the object that has the halo attached rather than the full halo. The Halo appears fully ok if I remove the background image. The Halo does appear in the Scene view window in 3D mode even with the background image added but not in the Game view window.

I have tried putting the background on a different sorting layer etc without success. The gameobject the halo should appear around is just a standard cube object as I am prototyping my game before I use own sprites. I am thinking its some sort of issue with rendering. Anyone have any tips or workaround.