Smoke Particle Lighting is view-dependent, and doesn't receive shadows

This is the “Effects” level from “Content Examples”.
I made some changes to sample 1.8 - I’d like to get realistic per-pixel lighting on the smoke.

On the spotlight, I activated translucent lighting and translucent shadows.
I changed the material to Translucent and “Surface ForwardShading”. I also activated Screen-Space Reflections on the particle material (because the doc says that’s important when using translucency).

Now, I experience two problems:

Problem 1: Shading is view-dependent
When I change the viewing angle (without changing the camera position), the illumination on the smoke cloud changes completely.
It looks as if the illumination is calculated in screen space.
How can I fix that, and get consistent shading no matter the viewing angle?

[Video of the problem - click here][3]

My scene setup:

Problem 2: Particles don’t receive shadows
When I add a small pole, then it casts shadows on the ground perfectly, but the particles remain unaffected from the shadow.

I am thankful for any advice. Shadow, texture and effects quality is set to “Epic” and I’m running on DX11.