Requesting general Lighting/Lightmapping guidance - Underground Sewer

Added a sweet dust particle effect, but getting yet more issues :confused:
Every time I bake I get seemingly nothing. No bounce or anything, haven’t changed the settings from a few days ago. Do these lightmaps look normal?

edit: Actually scratch that, seems like the scene is baking properly but I’d reset the global illumination multiplier in the post process volume. Here’s what the scene looks like with the dust particles:

Working on some moss/crack decals to make the roof/floor look more interesting. Come to think of it, I am actually having another issue - the backfaces of my tarp curtain are rendering black in scene, but they seem fine in the asset viewer;

Material is Surface, Opaque, and Two Sided with the two sided checkbox ticked.

Actually never mind on that one as well haha, I had a bunch of errors I should have sorted earlier in the log (“more overridden materials on static mesh component”). Apparently this is caused when you add a static mesh with multiple materials, then reimport it with less materials. Basically the static meshes in the scene used to have more materials than they have now.

edit: UE4 is freezing in the background a lot today, shame that’s never happened before and shame that it’s happening today of all days. Pray for me.