[UE5.3] Weird big pixles shadow on wall and floor

Development Rendering
,
1

Hi all,

I’m having this super weird shadow like effect that I can not seem to fix. It shows in random spots.
I remember someone told me to use the commands r.Lumen.Reflection.SOMETHING to fix it but I might be mistaken on dreaming.
Info:
I’m using UE5.3
The whole scene is a Datasmith assets.

Please watch the video to see the shadow like effect and help me fix it.

Thank you very much.