For context
Each tile that you see on the floor is a big (300x300) cube perfectly placed next to one another. It has been converted from BSP into static mesh, exported into Blender, painted atop of a nice UV with enough paddings around each island, and then imported back into Unreal (4.27). The room is light up by an emissive material that lights up everything else without problems. I’ve played around with UV shape (separate islands; seamed T-shape; scaled UV to cover only one side of the cube; etc), lightmap resolution, texture image sizes, etc. Nothing seems to help. When the cube stands alone, it creates a similar effect when looked at from a distance (img1). It also renders a random shadow in corners and edges (img2).
Unfortunately, I’m stuck with using tiled cubes as floor due to the game’s design (modular levels). I’ve tried applying this material onto a huge plane, and it works fine, but that’s not the way I’d like to go since it creates questions for vertical walls and non-rectangular geometry to complete the level. If anyone knows how to deal with this - I’d greatly appreciate any suggestions to try or values to check.