I’ve tried baking in the render scene, with the big cube and post process volume, and it keeps throwing the 'large actor receives a pre-shadow and will cause a huge perf hit…" error. Plus, Lightmass crashes and outputs a ‘cannot divide by zero’ error. I’m not sure what’s causing those. I ensured most settings were at default except for the spot lights which I decreased the cone angles a bit, and decreased brightness / temperature a bit too. Skylight, I changed source angle to 0.5 in the two settings for it. The shadows of the character are there. The rest of the scene looks ok.
I had changed the textures only for render D in terms of Brightness (0.75), Brightness Curve (1.25), and Saturation (1.25). For all renders I also disabled the Volumetric Shadowing, and Ray Tracing lighting and shadowing in the skylight and directional. I had increased a couple settings in Atmospheric Fog, which were Sun Multiplier and Inscatter Altitude Sample Num, and checked “Disable Ground Scattering”. Other than the change of Mip Gen Settings, the other changes I made were only to the lighting values. I don’t know why it was darkening the color so drastically. I thought it was possibly indirect intensity, so I increased it to 2 in one of the lights (directional I think), and it merely made the character look desaturated again. A bit ago I changed almost all values back to default, except for directional brightness at 10 lux, and the character has returned to the desaturated look and higher roughness appearance (not as glossy). That’s a stationary bake, too. Now, after a static bake at the same settings otherwise, both Preview and Production are resulting in a bit less desaturated and a bit worse shading.
There could be an issue with how the AORM and BaseColor textures are getting rendered in static bakes. Stationary never results in a lower quality of shading that’s so noticeable. It’s probably also connected to the normals in Unreal Engine, not an external texture issue.