Weird reflection effect after converting a bsp brush to a static mesh

I wanted to create a doorway with two different materials on each side for my project. This lead to me placing out a bsp brush box, scaling it up like a wall and applying two different materials on each side. Since the view port lags and becomes unusable upon having too many bsp brushes in the scene i converted it into a static mesh and cut out a doorway with the boolean function in the modeling mode. The only problem now is that when i point my characters flashlight in it’s direction i get this strange, glossy light reflection as seen on the picture in my post.

Why does this happen and are there any way to fix this in unreal engine 5.5.6?

maybe try remesh in the modeling tab on this wall if there is no reflection in your material