Frustum culling only stops rendering gameobjects to the left of the camera

So I'm making a platformer and am using quite a bit of Xffect effects. I didn't know what frustum culling was until today but I noticed when I start the scene (start left, move right) the tris are about 15,000 as I move right the tris start decreasing. So then I tried standing to where the effect was on the left border of the cam and moved left and right and the tris increased and decreased. I don't get the same thing when the effect is on the right border. I'm not sure why. Orthographic cam and moving on the X axis