Pretty sure he's talking about that giant blue/grey tinted stain in between the arches ;) ....or, actually, is it the other way around? are you talking about the orange light that's bleeding in?
If you're talking about this: https://i.imgur.com/12FuUuk.png That doesn't look like lightmap bleeding, that's just the default SSAO, which won't get a perfect silhouette of your mesh.