Something else must have been at play too, though, because I have manuel, always delevel in most fights, and usually go back to arena when mafia reports 100%, and never have this problem. I don't fully automate my fights, though (playing in relay browser, button-clicking on native macro).
Automation couldn't have been the cause, since I don't use any automation during ascension and I saw it.
The first Ed ascension for people is useless for testing this fix, since there are new monsters not yet in Manuel and KoLmafia doesn't know about them yet.