When i make more than one 3d floor under water (e.g. pipe or ladder) only upper looks normal, others rendered with only flats. I make in this case water alpha equal to zero, and to make water surface visible i place translucent sheet where is water level is. But this is stupid way because gzdoom render 3d floors very slowly and i don't want to see ghost traces each time when i look on them. In legacy port (which render 3d floors much much faster, about twice) i don't have render bugs like that. I tried all posible ways to solve this problem, and looks like he must be fixed only by the developers.