Hi @NASRHYM
Are you using LUMEN in this scene?
I had a similar issue early on with flat surfaces that had no textures.
In fact see the striation on the wall to the right (the horizontal bands) in the screenshot I took of your video.
I am sure I had a similar problem until I added some textures.
As you are using UE5, just grab some Quixel Bridge surfaces and throw them on your geometry to see if it helps - nice and easy since it is integrated into the editor.