On koth_distill, I've had this weird bug pop up recently where my water tunnel, which contains 3 separate water brushes, is bugging out. The middle brush is lower than the other two in order to not go though the lowered control point area. However, when you are in any of the three brushes and you are lower than top of the middle brush, the areas of the side brushes that are higher up than the middle brush are invisible, and you just see the skybox or any other geometry between them and the skybox. I have created a diagram to illustrate this. This isn't happening in the a5 version that is out, but for some reason it's happening on the version I'm currently working on.