I have a glass patio roof with a 15° incline. The robot only moves around in a circle or semi-circle on the spot. So @Stardustone's statement is not correct. At first I thought Galaxus had sent me a device that was not perfect. I then tested the device on a window and it worked perfectly there.

No, the robot can only clean glass surfaces with a tilt angle of 60 - 120 degrees. Terrace roofs do not normally fall under this. Other statements about this are incorrect.

Yes, this also works, it is even easier for the robot than if it is allowed to climb up and down a normal window.