I have a Pages document that contains one big table. I activated Screen View just to see what it looked like. I found that it was a completely useless feature so I deactivated it. I then noticed that the formatting of the table was completely changed: each row was very large (before that the size of each row was carefully chosen by me). I tried to "cancel", but nothing changed. I quit and reopened the document. At first I thought it was fixed, because the rows seemed to be the correct size. But then, scrolling through the document, I noticed to my horror that many rows were just repeated throughout the table, i.e., copy/pasted in more or less unpredictable ways. In a few minutes my carefully crafted document was randomly scrambled and mixed.
I miss the (now very distant) days when Apple was synonym with "it just works".