I use my joe with the "tite" (or rather: without "notite") option, that is, it switches to the "alternate screen" of terminal emulators. When I quit the editor, it completely disappears and the previous contents of my terminal are restored.
This is no longer the case if I accidentally invoke one of the aspell functions, bound to Alt+N and Alt+L by default. If I do so, after completing the given action joe's regular editor screen comes back, but this time on the "normal screen" of the terminal.
One way to immediately see this is e.g. in gnome-terminal produce some output (more than one page, e.g. seq 500) before launching joe. Notice that the scrollbar occupies part of the window's height, as expected. As you start up joe, by switching to the alternate screen the scrollbar is gone (or takes up the entire height) and you cannot scroll back. This is what I expected. After an aspell action, the scrollbar is partial again, and you can scroll back to see earlier terminal activity.
When you quit joe, joe's UI will remain there in the terminal. The end of the previous command's (e.g. seq's) output is truncated, it got overwritten by joe.
joe should remain on the alternate screen.
Yup, seeing this all the time now that tite is the default.