Post Process effect on 3D widget?

I’m trying to create a retro PC style for my spaceship UI.
I want to reach effects like CCTV screens or 8 - 16 bit.
I started with some render target system but I finally decide to isolate 3D widgets of spaceship UI with custom depth and add a post process volume to scene (unbounded) with retroPCmat as a post process material.
This material work if i set render with custom depth to a static mesh; but if i set render with custom depth to a generic 3D widget nothing appears. I read this topic How to disable depth test for 3D UMG widget ? - Rendering - Unreal Engine Forums but also turning on “disable depth test” of Widget3DPassThrough material the result is the same.