Water Shadow Bug

Hey guys,

I have a weird issue. Iam working on a 360° rendering of a cave with some water in it. Everything looks fine except the water. If you look closely you can see that there are really, really weird black shadows at the edges of the water. And the water also does not appear “clear” but “foggy”. The scene only has one directional standard light coming from the top. Lumen and Hardware Raytracing is enabled. Anyone has an idea what might cause this issue? Iam close to giving up on it…