And another bug report for Unity 2020.1 and later: 1. When editing a prefab "In Context", in other contexts than "Normal", (i.e. Gray or Hidden), most custom geometry also keeps rendering. That means that if you have a Jovian at 0/0/0, you must edit your prefabs in very dense fog. See mouse cursor near context buttons. 2. Furthermore, these objects render even into the pure prefab stage (the blue one that you get by double-clicking a prefab). See mouse cursor near bottom of screen. That's especially bad because in that case, most prefabs are at 0/0/0 and anything from the normal editor scene isn't even supposed to be rendered.