Every other bit of analysis is calculated at the Computational Height, but Room Separators sit on the Level, which means that if there is a slight bit of raised floor, they disappear under it, despite calculating at a different level.
Making them display at the Computation Height, would both make it easier to understand the calculation height as a principle, and also mean in plans that the room boundary wouldn't disappear behind low elements.
Alternatively have a show in foreground option!