Hi, did you check face orientation? Might help with panels that aren't extruding in the same direction. I don't know how adept you actually are with blender. Therefore sorry in advance if I'm telling you obvious things.
Subtle Paneling on the Engineering hull, registry! Solidify definitely hates me, and extrude and I are barely talking. I need a way to extrude down in the normal direction to all surfaces, which is obviously not happening.