Overlay transparent custom shader over Shapes

I am making this custom green rotation shader which is attached to a plane hovering over the plane of the doors and windows which are drawn using Shapes. I can't get the green bar to appear above the shapes; any thoughts?
The blending mode of the green shader on the screenshot attached is as below but the same issue occurs when the blending is opaque

Blend SrcAlpha OneMinusSrcAlpha // Traditional transparency
ZWrite off