Strange lighting Unreal 5

So from REVIT to Datasmith, then into Unreal 5, and many parts of the building looks like this.
Any ideas why?

At first glance it looks to me like a combination of whatever material is on those parts having a very low roughness, and low res Lumen reflections.

Could be wrong, not always easy to tell from a still image. But that would be my guess.

Also do your mesh walls/floors have at least 10cm thickness? Lumen can come up with weird lighting results otherwise.

Thank you for the quick response.
Actually I did apply a simple flat color material to those areas. no textures or bump, just plain color.
I Also checked to to none Nanites, thinking it could be that. But still the same, I usually use Datamisth from 3D Max, in this case it was straight from REVIT, I wonder if there is a normal issue or some strange tesselation problem.
Here is other screenshot, you can see that the wireframe of the geometry is straight, but the visual or display is wrong.

Well, I figured out, some way I have activated the view lumen scene mode on the viewport.
Not sure how that happened but when restored to the regular view mode, the geometry looks fine.
I post it here if anyone else finds the same issue.