I know you said you disabled static lighting, but could the fan have a lightmap issue? It shouldn’t matter if the scene is lit dynamically, but lightmaps have always given me trouble in my experience. The lightmap UVs on the fan could be overlapping, resulting in it being lit incorrectly. But as I said, I don’t believe lightmaps are utilized in a dynamic scene, so I’m not sure.
Is the blend mode in the fan’s material set to translucent by chance? In a little example I put together, a material with its opacity set to 1 is still casting a colored point light shadow. I’m using UE5 so things might be different, but I’m curious if this has anything to do with your problem.
You would expect the shadow to be black since the material is fully opaque, but is instead the color of the material.