Normal map rendering differently when Directional Light switched between Stationary to Static

Hey there forum folks. I’m digging into learning UE4 and have run into a question / problem when trying to get a better understanding of the difference between Static / Stationary / Movable lights. I have a simple setup with one of the Quixel Megascan assets, a directional light and a sky light. When I do a lighting bake with directional light set to ‘Stationary’ I see all of the nice details in the rock’s normal map. When the light is switched to ‘Static’ all of the rocks appear much smoother - almost as if the normal map isn’t being evaluated at all? I’m working in UE 4.24.3. The lightmap resolution is 1024, turning it up to 2048 doesn’t have any discernible difference - and the asset appears ‘red’ in the Lightmap Density optimization view mode when set to 2048.

Lighting Quality settings in the bake were all set to ‘High’. Setting it to ‘Preview’ up through to ‘Production’ didn’t seem to affect this issue.

Thanks in advance for any help you can offer.