Why, when I’m saving a change in one text-editing window (in any view), does the text I was previously viewing in another window (in view #4 or #5) disappear?
If I understand your question properly – you have multiple open windows or view of documents and find that editing and saving text in one of them makes the text displayed in the others disappear – I cannot replicate that.
I often have multiple text documents open and and editing an saving changes among them. What I do in one window or view doesn’t affect the other windows or views (except in the case where I’m viewing the same text in both an open document window and in the text pane of a view window).