I have been unable to find a solution for these problems and it only seems to occur with Lumen and Exponential height fog enabled. I am using Epic scalability, and have tried two-sided lighting and shadows option in both materials settings and Details Panel, and all light shadow options to no effect.
Any light source will shine through any mesh with both enabled, I have used directional, rectangle, and point lights in this example. All of them show as a single spot of light passing through objects. In addition, while moving the camera around the lights will ‘lag’ behind, making a ghosting effect that takes several seconds to fade out, leading to laser beams of leftover light dragged across the screen.
Height fog also behaves strangely, as it will become much darker when the camera is angled toward the directional light source, and then brighter again when turned away. Height fog density also seems to scale differently between the editor and playing the game, being much less dense during play.
I’m sure I’m just missing a setting or checkbox somewhere, but I have no solutions at the moment.