weird patterns on the walls

hello, i have weird patterns on the walls of this house, i tried many things i found on the internet but nothing fixed it, i added a cube inside the house and it worked perfectly, i moved a wall inside the house and it also worked perfectly, but when i move the walls where i want them to be then weird patterns appear

To me, it looks like you’ve got bad lightmap coordinates on those meshes. Lightmaps are textures on to which shadows are baked during the static-lighting-baking process. Do they only appear once the lighting is baked? You’ll most likely need to edit the meshes in an external 3D editor.

thanks for your answer, but what about last 2 screenshots? In screenshot_4 wall has this weird pattern but in screenshot_6 i moved the same wall from behind inside the house, and the wall inside the house looks fine to me, no patterns. isn’t that weird?

Do the patterns spontaneously appear after movement or is it only after a lighting bake?

The issue is definitely overlapping UV’s. Try to fix that first and see if you continue to have other issues.

hello, sorry for replying so late. i uploaded a video on youtube so you can understand better what i mean