Bug. When starting the game and then loading a saved game with underground pipes (only time it happens), underground pipes are invisible.

Work around Click on any bottom menu icon and pipes show up.

This is a minor bug and easily ignored.

This bug only showed up in the latest update. Did not happen yesterday.

Fixed in 0.9.19. It was an integer overflow: the x-ray thought a build tool was always open and stayed hidden until you actually clicked one — that's why your workaround worked. Update and it shows right away after loading.

😀👍