I have a room with sloped ceilings and various wall heights as shown. I drew the room as a rectangular room, and split the side wall twice to make the slopes. The walls form a contiguous rectangle, with heights that match piece-by-piece. I would expect "ceiling height from nearest wall" to work fine, but please see the image. It does not. What is wrong?

Thanks in advance for any help. Image at: https://imgur.com/a/nn1w0fm