Light Leak question

There is this scene I’m doing to test lighting. And a small thing keeps bugging me.
As seen on the picture there is a small light leak below the wall. Wall is “floored”, even deep into the floor yet light keeps comming through.
Assets I’m using are from Infinity Blades pack in Unreal Marketplace.

Here is the picture of the Lightmap UV’s of that mesh:

Placing another wall did fix the problem.
So is it the Lightmap UV problem? Is there another solution than replacing it with a different mesh?

Generally you can get rid of it by increasing lightmap resolution for object in question(floor in your case), and/or increasing overall static lighting quality. Or place or some sort of trim geometry there.

You lightmaps are split too much which can make it more difficult to get a good lighting result (wastes UV space and requires a higher lightmap resolution).
But also, if a mesh is on top of another surface then the pixels of the shadow it casts will not line up with the mesh itself which means you’ll get bleeding from underneath, whether it’s the shadow or light from outside. You either need to increase the lightmap resolution or have the floor cut out around the corners where the walls come to the floor so that it can’t bleed.