Discussion of Bryophyllum disease (Part 1 of Group 3)

This group of photos is a collection of leaf spots. The first photo is of Xiaoying's leaves. Cultivation began at the end of 1998, and the whole pot is still alive now. It is just growing rather slowly. Its leaf spots are carried through successive generations, and when itflowers, the petals also have similar markings. Is this actually a disease, and what disease is it? Please point it out, experts. (Zheng Yuhui)