HI NoaScape -
You are Spawning the Emitter attached to the object. Anytime anything is attached to another actor it will inherit the scale of the previous actor. I would recommend using the Spawn Emitter at Location for the walls as they are static in nature. If you do need the effect to attach to an object you will need to call a check of the object’s scale and feed in a Size Over Life Correction into the Spawner like this:
Thank You
Eric Ketchum