[5.3] Lumen black spots?

Hey there, I’m pretty new to Lumen and lightning in general, but I keep getting these “black spots” kind of errors on most surfaces. It kind of feels like the bottom of an ocean floor effect. Anyone knows what’s the matter with it and how to avoid it?

The setup for this map is the Basic template one from UE5, with a landscape with a couple of megascans materials on it (with nanite displacement enabled).